Merge pull request #139 from BastiaanOlij/fix_submodule

fix submodule link

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "godot_headers"]
 	path = godot_headers
-	url = [email protected]:GodotNativeTools/godot_headers.git
+	url = https://github.com/GodotNativeTools/godot_headers