doc: fix mistyped extension name.

doc/changelog.dox

@@ -130,9 +130,9 @@ See also:
     extensions on GLES 3.1+, exposed as @ref GL::Texture::view() and similar
     APIs on other texture types
 -   Implemented the GL 4.5 @gl_extension{ARB,clip_control} extension and
-    matching @gl_extension{EXT,clip_control} and
-    @webgl_extension{WEBGL,clip_control} extension on GLES and WebGL, exposed
-    as @ref GL::Renderer::setClipControl(). See also [mosra/magnum#543](https://github.com/mosra/magnum/issues/543).
+    matching @gl_extension{EXT,clip_control} extension on GLES and WebGL,
+    exposed as @ref GL::Renderer::setClipControl(). See also
+    [mosra/magnum#543](https://github.com/mosra/magnum/issues/543).
 -   Implemented @gl_extension{EXT,texture_norm16} and
     @webgl_extension{EXT,texture_norm16} ES and WebGL extensions, making
     normalized 16-bit texture and renderbuffer formats available on all