Log Message:
www/ruby-actionview51: update to 5.1.7

Update www/ruby-actionview51 to 5.1.7.

pkgsrc change: add "USE_LANGAUGES=	# none".

## Rails 5.1.7 (March 27, 2019) ##

*   Fix issue with `button_to`'s `to_form_params`

    `button_to` was throwing exception when invoked with `params` hash that
    contains symbol and string keys. The reason for the exception was that
    `to_form_params` was comparing the given symbol and string keys.

    The issue is fixed by turning all keys to strings inside
    `to_form_params` before comparing them.

    *Georgi Georgiev*