dev-lisp/sbcl: Remove useless maintainer <description/>

Remove useless/redundant maintainer <description/>. It does not benefit
bug wrangling, and only wastes developer's time on reading it. Few tips:

- assignee/CC is implied by ordering, there is no reason to repeat it,
- we know that maintainer is maintainer (la la la la la),
- most of adjectives for maintainer are of no value and/or are obvious.

dev-lisp/sbcl/metadata.xml

@@ -4,12 +4,10 @@
 	<maintainer type="person">
 		<email>pchrist@gentoo.org</email>
 		<name>Panagiotis Christopoulos</name>
-		<description>primary-maintainer</description>
 	</maintainer>
 	<maintainer type="person">
 		<email>bugs@cddr.org</email>
 		<name>Stelian Ionescu (fe[nl]ix)</name>
-		<description>second-maintainer</description>
 	</maintainer>
 	<maintainer type="project">
 		<email>common-lisp@gentoo.org</email>