fix #1005: don't exclude /var/log/?* with stdexcludes

the old behaviour can be easily restored with --exclude-path
and this seemed to surprise a lot of users.

PVE/CLI/vzdump.pm

@@ -119,7 +119,6 @@ You can specify a hook script with option C<--script>. This script is called at
 
 vzdump skips the following files wit option --stdexcludes
 
- /var/log/?*
  /tmp/?*
  /var/tmp/?*
  /var/run/?*pid

PVE/VZDump.pm

@@ -558,8 +558,7 @@ sub new {
     }
 
     if ($opts->{stdexcludes}) {
-	push @$findexcl, '/var/log/?*',
-	                 '/tmp/?*',
+	push @$findexcl, '/tmp/?*',
 	                 '/var/tmp/?*',
 	                 '/var/run/?*.pid';
     }