patch 8.1.2355: test with "man" fails on FreeBSD

Problem:    Test with "man" fails on FreeBSD.
Solution:   Use "-P" instead of "--pager".
diff --git a/src/version.c b/src/version.c
index b3b48d4..4ca5c0f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -738,6 +738,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2355,
+/**/
     2354,
 /**/
     2353,