fix constness

dbms/include/DB/Common/Exception.h

@@ -88,7 +88,7 @@ void tryLogException(std::exception_ptr e, Poco::Logger * logger, const std::str
 std::string getExceptionMessage(std::exception_ptr e, bool with_stacktrace);
 
 
-void rethrowFirstException(Exceptions & exceptions);
+void rethrowFirstException(const Exceptions & exceptions);
 
 std::unique_ptr<Poco::Exception> convertCurrentException();
 

dbms/src/Common/Exception.cpp

@@ -139,7 +139,7 @@ std::unique_ptr<Poco::Exception> convertCurrentException()
 }
 
 
-void rethrowFirstException(Exceptions & exceptions)
+void rethrowFirstException(const Exceptions & exceptions)
 {
 	for (size_t i = 0, size = exceptions.size(); i < size; ++i)
 		if (exceptions[i])