patch 8.1.0304: no redraw when using a STOP signal on Vim and then CONT

Problem:    No redraw when using a STOP signal on Vim and then a CONT signal.
Solution:   Catch the CONT signal and set the terminal to raw mode.  This is
            like 8.1.0244 but without the screen redraw and a fix for
            multi-threading suggested by Dominique Pelle.
diff --git a/src/version.c b/src/version.c
index d382ff3..8fa17ec 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    304,
+/**/
     303,
 /**/
     302,