Move ubuntu-trusty image pause to correct section

The pause setting for the ubuntu-trusty image builds should be in
the diskimages entry for it, not its labels entry. Move it to the
appropriate section.

Change-Id: Iceb43923104fd5624aab0fc50c9426664e1230cb

nodepool/nodepool.yaml

@@ -43,7 +43,6 @@ labels:
       - name: citycloud-la1
       - name: citycloud-sto2
   - name: ubuntu-trusty
-    pause: True
     image: ubuntu-trusty
     ready-script: configure_mirror.sh
     min-ready: 1
@@ -1203,6 +1202,7 @@ diskimages:
       DIB_DISTRIBUTION_MIRROR: http://ftp.us.debian.org/debian/
       DIB_GRUB_TIMEOUT: '0'
   - name: ubuntu-trusty
+    pause: True
     elements:
       - ubuntu-minimal
       - vm