need to use --whatprovides

This ensure we also check for other packages which are used instead
of the requested one, which does not work with rpm -q:

[root@brett ~]# rpm -q vim
package vim is not installed
[root@brett ~]# yum --assumeyes --quiet install "vim"
Package 2:vim-enhanced-7.3.056-1.fc14.x86_64 already installed and
latest version
[root@brett ~]# rpm -q --whatprovides vim
vim-enhanced-7.3.056-1.fc14.x86_64

Signed-off-by: Nico Schottelius <nico@kr.ethz.ch>

conf/type/__package_yum/explorer/pkg_version

@@ -27,4 +27,4 @@ else
    name="$__object_id"
 fi
 
-rpm -q "$name" 2>/dev/null || true
+rpm -q --whatprovides "$name" 2>/dev/null || true