Removing error check if an ASCII writer has been properly finished.

Turns out that in error situations, the final finish message might not
reach the writer anymore, as communication between the threads will be
shut down. Instead of aborting, we now just clean up in that case and
proceed. This isn't changing any other behaviour. The original error
check was in place mostly for helping debug the data flow between the
threads anyways.

Addresses BIT-1331.

src/logging/writers/ascii/Ascii.cc

@@ -181,10 +181,9 @@ bool Ascii::InitFormatter()
 Ascii::~Ascii()
 	{
 	if ( ! ascii_done )
-		{
-		fprintf(stderr, "internal error: finish missing\n");
-		abort();
-		}
+		// In case of errors aborting the logging altogether,
+		// DoFinish() may not have been called.
+		CloseFile(network_time);
 
 	delete formatter;
 	}