fix fake flag detection in exploit_embed

Author: st0ffregen

checker/src/checker.py

@@ -572,9 +572,9 @@ async def exploit_embed(
             flag += closest_char
 
         if flag:
-            unformatted_flag = await unformat_flag(flag)
-            if unformatted_flag.endswith("FAKE"):
+            if flag.endswith("FAKE"):
                 continue
+            unformatted_flag = await unformat_flag(flag)
             logger.debug(f"Flag found. Original: {flag}   Unformatted: {unformatted_flag}")
             return unformatted_flag