patch 9.0.1588: Incsearch not triggered when pasting clipboard register

Problem:    Incsearch not triggered when pasting clipboard register on the
            command line.
Solution:   Also set "literally" when using a clipboard register. (Ken Takata,
            closes #12460)
diff --git a/src/version.c b/src/version.c
index 08c67bb..34c8456 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1588,
+/**/
     1587,
 /**/
     1586,