Unconditionalizing a step so that ubuntu;debian output is correct

for glance database configuration.

Cherry-pick from https://review.openstack.org/#/c/53456/

Change-Id: Ie79ae4223da968a67a4c7b497ba57dcc4870b856
Closes-bug:1243925

doc/install-guide/section_glance-install.xml

@@ -24,7 +24,7 @@
       <screen os="rhel;centos;fedora"><prompt>#</prompt> <userinput>yum install openstack-glance</userinput></screen>
       <screen os="opensuse;sles"><prompt>#</prompt> <userinput>zypper install openstack-glance python-glanceclient</userinput></screen></step>
 
-    <step os="rhel;centos;fedora;opensuse;sles"><para>The Image
+    <step><para>The Image
         Service stores information about images in a database.  This
         guide uses the MySQL database that is used by other OpenStack
         services.</para>
@@ -52,7 +52,6 @@
 sql_connection = mysql://glance:GLANCE_DBPASS@localhost/glance
 ...
       </programlisting>
-
 </step>
 
     <step os="rhel;centos;fedora;opensuse;sles">