patch 8.0.0442: patch shell command not well escaped

Problem:    Patch shell command uses double quotes around the argument, which
            allows for $HOME to be expanded. (Etienne)
Solution:   Use single quotes on Unix. (closes #1543)
diff --git a/src/version.c b/src/version.c
index aee70ef..0f7b4e4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    442,
+/**/
     441,
 /**/
     440,