Core/Misc: Multiple static analysis issues fixed (small optimizations and clear code)

src/server/scripts/Commands/cs_guild.cpp

@@ -249,7 +249,7 @@ public:
     {
         Guild* guild = nullptr;
 
-        if (args && strlen(args) > 0)
+        if (args && args[0] != '\0')
         {
             if (isNumeric(args))
             {