add workaround for if-none-match of unsafe methods
add workaround for if-none-match of unsafe methods

Some http libraries (I'm looking at you, iOS, but probably many others)
add if-none-match to unsafe methods even when they weren't told to.
This hack allows view code to decide it wants to violate 14.26 and
ignore the if-none-match header.

fusic-com/flask-webcache