[RELEASE] Armor artifact signature on the download page
An ASF bot told me:
```
Also, I've just noticed that all the .ASC files are binary.
They are supposed to be ascii-armoured.
As it stands, the wrong content-type will be applied which may cause issues
with downloads.
```
diff --git a/docs/modules/community/pages/release.adoc b/docs/modules/community/pages/release.adoc
index c66ba2f..f03df3b 100644
--- a/docs/modules/community/pages/release.adoc
+++ b/docs/modules/community/pages/release.adoc
@@ -186,7 +186,7 @@
# $2: Key footprint to use for signing
sha512sum $1 > $1.sha512
-gpg -u $2 --output $1.asc --detach-sig $1
+gpg -u $2 --output $1.asc --detach-sig --armor $1
svn add $1
svn propset svn:mime-type application/octet-stream $1
svn add $1.sha512
