help: add a missing blank line to unhide `revlog-compression`
The help was output, but it was elided with "Enabled by default" from the
previous item.
--- a/mercurial/help/config.txt Fri Jun 21 03:50:40 2019 +0200
+++ b/mercurial/help/config.txt Sat Jun 22 23:04:52 2019 -0400
@@ -866,6 +866,7 @@
Repositories with this on-disk format require Mercurial version 4.7
Enabled by default.
+
``revlog-compression``
Compression algorithm used by revlog. Supported value are `zlib` and `zstd`.
The `zlib` engine is the historical default of Mercurial. `zstd` is a newer
--- a/tests/test-help.t Fri Jun 21 03:50:40 2019 +0200
+++ b/tests/test-help.t Sat Jun 22 23:04:52 2019 -0400
@@ -1509,6 +1509,8 @@
"sparse-revlog"
+ "revlog-compression"
+
"profiling"
-----------