Fix: Make switch on MD5File::ChecksumResult complete to avoid compiler warning

src/base_media_func.h

@@ -131,6 +131,9 @@ bool BaseSet<T, Tnum_files, Tsearch_in_tars>::FillSetDetails(IniFile *ini, const
 
 		file->check_result = T::CheckMD5(file, BASESET_DIR);
 		switch (file->check_result) {
+			case MD5File::CR_UNKNOWN:
+				break;
+
 			case MD5File::CR_MATCH:
 				this->valid_files++;
 				this->found_files++;