Docs: Add warnings about no SSL/(D)TLS revocation

(cherry picked from commit 4eb427afb8ef22631ccf261362c1bb49776b987b)

doc/classes/HTTPClient.xml

@@ -10,6 +10,7 @@
 		For more information on HTTP, see https://developer.mozilla.org/en-US/docs/Web/HTTP (or read RFC 2616 to get it straight from the source: https://tools.ietf.org/html/rfc2616).
 		[b]Note:[/b] When performing HTTP requests from a project exported to HTML5, keep in mind the remote server may not allow requests from foreign origins due to [url=https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS]CORS[/url]. If you host the server in question, you should modify its backend to allow requests from foreign origins by adding the [code]Access-Control-Allow-Origin: *[/code] HTTP header.
 		[b]Note:[/b] SSL/TLS support is currently limited to TLS 1.0, TLS 1.1, and TLS 1.2. Attempting to connect to a TLS 1.3-only server will return an error.
+		[b]Warning:[/b] SSL/TLS certificate revocation and certificate pinning are currently not supported. Revoked certificates are accepted as long as they are otherwise valid. If this is a concern, you may want to use automatically managed certificates with a short validity period.
 	</description>
 	<tutorials>
 		<link>https://docs.godotengine.org/en/3.3/tutorials/networking/http_client_class.html</link>

doc/classes/HTTPRequest.xml

@@ -6,6 +6,7 @@
 	<description>
 		A node with the ability to send HTTP requests. Uses [HTTPClient] internally.
 		Can be used to make HTTP requests, i.e. download or upload files or web content via HTTP.
+		[b]Warning:[/b] See the notes and warnings on [HTTPClient] for limitations, especially regarding SSL security.
 		[b]Example of contacting a REST API and printing one of its returned fields:[/b]
 		[codeblock]
 		func _ready():
@@ -64,8 +65,6 @@
 		    add_child(texture_rect)
 		    texture_rect.texture = texture
 		[/codeblock]
-		[b]Note:[/b] When performing HTTP requests from a project exported to HTML5, keep in mind the remote server may not allow requests from foreign origins due to [url=https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS]CORS[/url]. If you host the server in question, you should modify its backend to allow requests from foreign origins by adding the [code]Access-Control-Allow-Origin: *[/code] HTTP header.
-		[b]Note:[/b] SSL/TLS support is currently limited to TLS 1.0, TLS 1.1, and TLS 1.2. Attempting to connect to a TLS 1.3-only server will return an error.
 	</description>
 	<tutorials>
 		<link>https://docs.godotengine.org/en/3.3/tutorials/networking/http_request_class.html</link>

doc/classes/PacketPeerDTLS.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		This class represents a DTLS peer connection. It can be used to connect to a DTLS server, and is returned by [method DTLSServer.take_connection].
+		[b]Warning:[/b] SSL/TLS certificate revocation and certificate pinning are currently not supported. Revoked certificates are accepted as long as they are otherwise valid. If this is a concern, you may want to use automatically managed certificates with a short validity period.
 	</description>
 	<tutorials>
 	</tutorials>