xwayland/xwm: make hints->input default to true
xwayland/xwm: make hints->input default to true

An X11 client can leave the hints->input WM hint unspecified,
by not setting the XCB_ICCCM_WM_HINT_INPUT flag in hints->flags.
In that case, we should assume a sane default.

Make the hint default to true, so that clients which do not specify
the hint, like mupdf, still get keyboard focus.

This should fix swaywm/sway#2231

swaywm/wlroots,ascent12/wlroots,SirCmpwn/wlroots,swaywm/wlroots,ascent12/wlroots