Parser: set timestamp to zero if parsing failed

When parsing of a timestamp failed (shouldn't happen) set the
timestamp to zero. This should give less unpredictable results
and silence a compiler warning.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/parse-xml.c

@@ -343,6 +343,7 @@ static void sampletime(char *buffer, duration_t *time)
 		time->seconds = (hr * 60 + min) * 60 + sec;
 		break;
 	default:
+		time->seconds = 0;
 		printf("Strange sample time reading %s\n", buffer);
 	}
 }