patch 8.0.1021: older Gnome terminal still echoes t_RC

Problem:    Older Gnome terminal still echoes t_RC. (Fracois Ingelrest)
Solution:   Check for version > 3000 instead of 4000.
diff --git a/src/term.c b/src/term.c
index faf3762..4244892 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4562,9 +4562,10 @@
 				&& STRNCMP(tp + extra - 2, "1;95;0c", 7) == 0)
 			    is_not_xterm = TRUE;
 #  endif
-			/* Gnome Terminal.app sends 1;4402;0, assuming any
-			 * version number over 4000 is not an xterm. */
-			if (col >= 4000)
+			/* Gnome Terminal.app sends 1;3801;0 or 1;4402;0,
+			 * assuming any version number over 3000 is not an
+			 * xterm. */
+			if (col >= 3000)
 			    is_not_xterm = TRUE;
 
 			/* Only request the cursor style if t_SH and t_RS are