tests/http: fix log formatting on wrong exit code

Closes #10868

Author: icing

tests/http/testenv/curl.py

@@ -162,7 +162,7 @@ def add_assets(self, assets: List):
     def check_exit_code(self, code: int):
         assert self.exit_code == code, \
             f'expected exit code {code}, '\
-            'got {self.exit_code}\n{self._dump_logs()}'
+            f'got {self.exit_code}\n{self._dump_logs()}'
 
     def check_exit_code_not(self, code: int):
         assert self.exit_code != code, \