*/*: remove proxied="yes" from metadata.xml

GURU don't have proxied maintainers.
Also remove two instances where proxy-maint was referenced

Signed-off-by: David Roman <davidroman96@gmail.com>

app-vim/vim-mediawiki/metadata.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
 <pkgmetadata>
-	<maintainer type="person" proxied="yes">
+	<maintainer type="person">
 		<email>zdanevich.vitaly@ya.ru</email>
 		<name>Vitaly Zdanevich</name>
 	</maintainer>