man: remove --nogpg from dnf install command line

Keys for previous and future Fedora distributions were added
for the fedora-repos package recently:
https://bugzilla.redhat.com/show_bug.cgi?id=1246701.
There is no need to skip signature checking.

Also, update to the latest and greatest and remove unnecessary quotes.

diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index 4b0e72113e78db4d8c2579ca7e22c70708ad3567..0925e9d1870fad7a7b24a6ebd3bbad3ee3bfdade 100644 (file)
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -850,7 +850,7 @@
     <example>
       <title>Build and boot a minimal Fedora distribution in a container</title>
 
-      <programlisting># dnf -y --releasever=21 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd dnf fedora-release vim-minimal
+      <programlisting># dnf -y --releasever=23 --installroot=/srv/mycontainer --disablerepo=* --enablerepo=fedora install systemd passwd dnf fedora-release vim-minimal
 # systemd-nspawn -bD /srv/mycontainer</programlisting>
 
       <para>This installs a minimal Fedora distribution into the