fixed cut and paste error

src/CivetServer.cpp

@@ -98,7 +98,7 @@ CivetServer::CivetServer(const char **options,
     }
     callbacks.connection_close = closeHandler;
     context = mg_start(&callbacks, this, options);
-    if (context == nullptr) throw CivetException::("null context when constructing CivetServer. Possible problem binding to port.");
+    if (context == nullptr) throw CivetException("null context when constructing CivetServer. Possible problem binding to port.");
 }
 
 CivetServer::~CivetServer()