Fix spurious comma in "Flags:" /region info output

When the "/region info" command displays any flags in the region,
it always prints an extra leading comma character after the
"Flags:" prompt.

src/main/java/com/sk89q/worldguard/bukkit/commands/RegionCommands.java

@@ -495,7 +495,7 @@ public void displayRegionInfo(CommandSender sender, final LocalPlayer localPlaye
                 continue;
             }
 
-            if (s.length() > 0) {
+            if (hasFlags) {
                 s.append(", ");
             }