patch 8.0.1483: searchpair() might return an invalid value on timeout

Problem:    Searchpair() might return an invalid value on timeout.
Solution:   When the second search times out, do not accept a match from the
            first search. (Daniel Hahler, closes #2552)

src/search.c

@@ -973,7 +973,16 @@ searchit(
 					      NULL, NULL
 #endif
 					    )) == 0)
+			    {
+#ifdef FEAT_RELTIME
+				/* If the search timed out, we did find a match
+				 * but it might be the wrong one, so that's not
+				 * OK. */
+				if (timed_out != NULL && *timed_out)
+				    match_ok = FALSE;
+#endif
 				break;
+			    }
 
 			    /* Need to get the line pointer again, a
 			     * multi-line search may have made it invalid. */

src/version.c

@@ -771,6 +771,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1483,
 /**/
     1482,
 /**/