patch 7.4.1551
Problem:    Cannot generate help tags in all doc directories.
Solution:   Make ":helptags ALL" work.
diff --git a/src/version.c b/src/version.c
index 4f66f9d..5d14270 100644
--- a/src/version.c
+++ b/src/version.c
@@ -744,6 +744,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1551,
+/**/
     1550,
 /**/
     1549,