Only process /etc/shorewall/rtrules if it is non-empty

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@3766 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb

Shorewall/compiler

@@ -1387,9 +1387,12 @@ __EOF__
 	    f=$(find_file rtrules)
 
 	    if [ -f $f ]; then
+		strip_file rtrules $f
+
+		if [ -s $TMP_DIR/rtrules ]; then
 		    progress_message2 "$DOING $f..."
 
-		strip_file rtrules $f
+		    save_command
 
 		    while read provider priority source dest; do
 			expandv priority provider source dest
@@ -1398,6 +1401,7 @@ __EOF__
 		    done < $TMP_DIR/rtrules
 		fi
 	    fi
+	fi
 
 	save_command "run_ip route flush cache"
 	INDENT="$save_indent"