Tell users how to clear the terminal in the error message

This is not completely obvious - when I first saw the message, I started
pressing backspace which really doesn't help.

Also clarify and shorten the message a bit - in "Could not execute the file
in the VTE because it probably contains a command" it's not clear if it's
the file or VTE which contains the command. Also use "terminal" instead
of "VTE" which is more user-friendly.

src/build.c

@@ -977,9 +977,9 @@ static GPid build_run_cmd(GeanyDocument *doc, guint cmdindex)
 		vte_cwd(working_dir, TRUE);
 		if (! vte_send_cmd(vte_cmd))
 		{
-			ui_set_statusbar(FALSE,
-		_("Could not execute the file in the VTE because it probably contains a command."));
-			geany_debug("Could not execute the file in the VTE because it probably contains a command.");
+			const gchar *msg = _("File not executed because the terminal may contain some input (press Ctrl+C or Enter to clear it).");
+			ui_set_statusbar(FALSE, "%s", msg);
+			geany_debug("%s", msg);
 			if (!vc->skip_run_script)
 				g_unlink(run_cmd);
 		}

src/vte.c

@@ -736,10 +736,9 @@ void vte_cwd(const gchar *filename, gboolean force)
 			gchar *cmd = g_strconcat(vc->send_cmd_prefix, "cd ", quoted_path, "\n", NULL);
 			if (! vte_send_cmd(cmd))
 			{
-				ui_set_statusbar(FALSE,
-		_("Could not change the directory in the VTE because it probably contains a command."));
-				geany_debug(
-		"Could not change the directory in the VTE because it probably contains a command.");
+				const gchar *msg = _("Directory not changed because the terminal may contain some input (press Ctrl+C or Enter to clear it).");
+				ui_set_statusbar(FALSE, "%s", msg);
+				geany_debug("%s", msg);
 			}
 			g_free(quoted_path);
 			g_free(cmd);