copr-be: don't fail the boot if lvm on md doesn't assemble

https://github.com/fedora-copr/copr/issues/3536

roles/copr/backend/tasks/mount_fs.yml

@@ -73,7 +73,7 @@
   file: state=directory path=/var/lib/copr/public_html
 
 - name: mount up disk of copr repo
-  mount: name=/var/lib/copr/public_html src='LABEL=copr-repo' fstype=ext4 state=mounted
+  mount: name=/var/lib/copr/public_html src='LABEL=copr-repo' fstype=ext4 state=mounted opts=nofail
 
 - name: mount /tmp/
   mount: name=/tmp src='tmpfs' fstype=tmpfs state=mounted