dev-haskell/hashtables: Remove proxy-maint

Remove proxy maintainer project from metadata, because there was no
proxied maintainer left.
Reported-By: Michael Mair-Keimberger
Package-Manager: Portage-2.3.11, Repoman-2.3.3

dev-haskell/hashtables/metadata.xml

@@ -4,10 +4,6 @@
 	<maintainer type="project">
 		<email>[email protected]</email>
 	</maintainer>
-	<maintainer type="project">
-		<email>[email protected]</email>
-		<name>Proxy Maintainers</name>
-	</maintainer>
 	<longdescription>
 		This package provides a couple of different implementations of mutable hash
 		tables in the ST monad, as well as a typeclass abstracting their common