Fix problem where group membership at startup hounded xCAT commands eternally

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@12741 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

perl-xCAT/xCAT/NodeRange.pm

@@ -243,6 +243,7 @@ sub expandatom { #TODO: implement table selection as an atom (nodetype.os==rhels
          {
             unless (scalar %allgrphash and (time() < ($allgrphashstamp+5))) { #build a group membership cache
 		$allgrphashstamp=time();
+        	%allgrphash=();
                 my $nlent;
 	            foreach $nlent (@allnodeset) { 
 	                my @groups=split(/,/,$nlent->{groups});