Fix return value of finduserstr()

was always returning 0 (oops), so user.tab searches for specific string values
(usually user's real name) did not work.

src/sbbs3/userdat.c

@@ -1472,7 +1472,7 @@ uint finduserstr(scfg_t* cfg, uint usernumber, enum user_field fnum
 	close(file);
 	if(progress != NULL)
 		progress(cbdata, unum, last);
-	return(0);
+	return found;
 }
 
 /****************************************************************************/