Fix doc for Dictionary.erase

(cherry picked from commit 1e0fe9f8179b7fb09a8f340a88b87d54edd776e6)

doc/classes/Dictionary.xml

@@ -111,7 +111,8 @@
 			<return type="bool" />
 			<argument index="0" name="key" type="Variant" />
 			<description>
-				Erase a dictionary key/value pair by key. Returns [code]true[/code] if the given key was present in the dictionary, [code]false[/code] otherwise. Does not erase elements while iterating over the dictionary.
+				Erase a dictionary key/value pair by key. Returns [code]true[/code] if the given key was present in the dictionary, [code]false[/code] otherwise.
+				[b]Note:[/b] Don't erase elements while iterating over the dictionary. You can iterate over the [method keys] array instead.
 			</description>
 		</method>
 		<method name="get">