[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

proxy/common/leakage.py

@@ -37,7 +37,7 @@ def release(self, tokens: int) -> None:
         E.g. say you wanted to read 1024 units, but only 24 units were read, then put
         back unconsumed 1000 tokens back in the bucket."""
         if tokens < 0:
-            raise ValueError("Cannot release a negative number of tokens")
+            raise ValueError('Cannot release a negative number of tokens')
         self.tokens += tokens
         self.tokens = min(self.tokens, self.rate)