[rails6][MiqServer] Use proper ActionView constructor
[rails6][MiqServer] Use proper ActionView constructor

This was changed in Rails 6:

https://github.com/rails/rails/commit/e17fe52e0e0ef0842b6c409e1110a862c4e005bc

And using `.empty` is good enough for our case since we are just trying
to access the helper method, `.number_to_human_size`, outside the
context of the views.

d-m-u/manageiq,d-m-u/manageiq,NickLaMuro/manageiq,lpichler/manageiq,d-m-u/manageiq,jrafanie/manageiq,jvlcek/manageiq,chessbyte/manageiq,skateman/manageiq,jvlcek/manageiq,skateman/manageiq,agrare/manageiq,skateman/manageiq,kbrock/manageiq,kbrock/manageiq,NickLaMuro/manageiq,jrafanie/manageiq,ManageIQ/manageiq,kbrock/manageiq,mzazrivec/manageiq,agrare/manageiq,chessbyte/manageiq,lpichler/manageiq,djberg96/manageiq,jrafanie/manageiq,ManageIQ/manageiq,chessbyte/manageiq,jvlcek/manageiq,djberg96/manageiq,mzazrivec/manageiq,lpichler/manageiq,jrafanie/manageiq,agrare/manageiq,NickLaMuro/manageiq,djberg96/manageiq,kbrock/manageiq,d-m-u/manageiq,mzazrivec/manageiq,ManageIQ/manageiq,lpichler/manageiq,djberg96/manageiq,jvlcek/manageiq,mzazrivec/manageiq,ManageIQ/manageiq,agrare/manageiq,chessbyte/manageiq,skateman/manageiq,NickLaMuro/manageiq