fixup! gluon-mesh-babel: implement neighbour check

package/gluon-mesh-babel/files/lib/gluon/state/check.d/has_neighbours

 #!/bin/sh
-out=$(echo dump | nc ::1 33123 | grep "add neighbour" 2>/dev/null) && [ -n "$out" ]
+echo dump | nc ::1 33123 | grep -qF "add neighbour"