patch 8.0.1059: older Gnome terminal returns smaller version number

Problem:    older Gnome terminal returns smaller version number. (antarestrue)
Solution:   Lower version limit from 2800 to 2500. (#2032)
diff --git a/src/term.c b/src/term.c
index 413d4bb..7fa08c3 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4572,12 +4572,12 @@
 				&& STRNCMP(tp + extra - 2, "1;95;0c", 7) == 0)
 			    is_not_xterm = TRUE;
 #  endif
-			/* Gnome terminal sends 1;3801;0 or 1;4402;0.
+			/* Gnome terminal sends 1;3801;0, 1;4402;0 or 1;2501;0.
 			 * xfce4-terminal sends 1;2802;0.
 			 * screen sends 83;40500;0
-			 * Assuming any version number over 2800 is not an
+			 * Assuming any version number over 2500 is not an
 			 * xterm (without the limit for rxvt and screen). */
-			if (col >= 2800)
+			if (col >= 2500)
 			    is_not_xterm = TRUE;
 
 			/* PuTTY sends 0;136;0 */