docs: Quote example url to workaround asciidoc bug

The example url in the section "Ways to refer to a bug" was causing
asciidoc to emit invalid xml (by closing a docbook ulink tag before the
closing semicolon for a &gt; replacement giving &gt</ulink>;) which
meant that xmlto could not then produce a man page. Quoting the url
seems to workaround this issue.

asciidoc version was 8.4.4

https://bugzilla.gnome.org/show_bug.cgi?id=621580

1 files changed, 1 insertions, 1 deletions

diff --git a/git-bz.txt b/git-bz.txt
index 1538562..648b4ec 100644
--- a/git-bz.txt
+++ b/git-bz.txt
@@ -267,7 +267,7 @@ Ways to refer to a bug:
 
 <alias>:<id>:: bug # on the given bug tracker alias (see below)
 
-<url>:: An URL of the form http://<hostname>/show_bug.cgi?id-<id>
+<url>:: An URL of the form "http://<hostname>/show_bug.cgi?id-<id>"
 
 [[add-url-method]]
 ADD URL METHOD