[trivial] Add newlines to end of log messages.

Log messages should terminate with a '\n', or the following log will be
written to the same line without a timestamp. Fix a couple of cases
where the message is not terminated with a \n.

src/init.cpp

@@ -668,7 +668,7 @@ void ThreadImport(std::vector<fs::path> vImportFiles)
     // scan for better chains in the block chain database, that are not yet connected in the active best chain
     CValidationState state;
     if (!ActivateBestChain(state, chainparams)) {
-        LogPrintf("Failed to connect best block");
+        LogPrintf("Failed to connect best block\n");
         StartShutdown();
         return;
     }