logging: Unconditionally log levels >= WARN

Messages with level `WARN` or higher should be logged even when
the category is not provided with `-debug=`, to make sure important
warnings are not lost.

src/timedata.cpp

@@ -99,7 +99,7 @@ void AddTimeData(const CNetAddr& ip, int64_t nOffsetSample)
             }
         }
 
-        if (LogAcceptCategory(BCLog::NET)) {
+        if (LogAcceptCategory(BCLog::NET, BCLog::Level::Debug)) {
             std::string log_message{"time data samples: "};
             for (const int64_t n : vSorted) {
                 log_message += strprintf("%+d  ", n);