Require Sprockets < 4
Require Sprockets < 4

Sprockets 4 does not support procs in config.assets.precompile which
we currently depend on in pageflow/engine.rb.

REDMINE-17098

tf/pageflow,codevise/pageflow,tf/pageflow,tf/pageflow,tf/pageflow,codevise/pageflow,codevise/pageflow,codevise/pageflow