fix(Core): uint32 assignment, prevent crash, closes #2433 (#2435)

* Fixed uint32 assignment, prevent crash

* Improved code quality

src/server/game/Chat/ChatLink.cpp

@@ -333,7 +333,7 @@ bool SpellChatLink::ValidateName(char* buffer, const char* context)
             {
                 // found the prefix, remove it to perform spellname validation below
                 // -2 = strlen(": ")
-                uint32 spellNameLength = strlen(buffer) - skillLineNameLength - 2;
+                uint32 spellNameLength = (strlen(buffer) <= skillLineNameLength + 2) ? 0 : strlen(buffer) - skillLineNameLength - 2;
                 memmove(buffer, buffer + skillLineNameLength + 2, spellNameLength + 1);
                 break;
             }