patch 8.2.3830: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/window.c b/src/window.c
index d3612b6..4ee75c1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -198,7 +198,7 @@
 		    if (Prenum == 0)
 			emsg(_(e_no_alternate_file));
 		    else
-			semsg(_("E92: Buffer %ld not found"), Prenum);
+			semsg(_(e_buffer_nr_not_found), Prenum);
 		    break;
 		}