fix for bug 3574: the blank grptype means static nodegroup

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/branches/2.8@16290 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server/lib/xcat/plugins/DBobjectdefs.pm

@@ -2144,7 +2144,9 @@ sub defch
 
             #  get the @memberlist for static group
             #    - if provided - to use below
-            if ($grptype eq 'static')
+            #  if the static group is not defined in the nodegroup table
+            #  the grptype will be undef
+            if(!$grptype || ($grptype eq 'static'))
             {
 
                 # check for bad cmd line options