Remove extra semi colon from proxygen/lib/http/session/HTTPTransactio…

…n.cpp

Summary:
`-Wextra-semi` or `-Wextra-semi-stmt`

If the code compiles, this is safe to land.

Reviewed By: dmm-fb

Differential Revision: D51777907

fbshipit-source-id: 59b1c55ac084d8c47897c81f06638a579e7eab67

proxygen/lib/http/session/HTTPTransaction.cpp

@@ -55,7 +55,8 @@ HTTPException stateMachineError(HTTPException::Direction dir, std::string msg) {
     invariantViolation(                                                   \
         HTTPException(HTTPException::Direction::INGRESS_AND_EGRESS, #X)); \
     return;                                                               \
-  }
+  }                                                                       \
+  static_assert(true, "semicolon required")
 
 uint64_t HTTPTransaction::egressBufferLimit_ = kMaxBufferPerTxn;