backend/ipp.c: Synch color settings earlier in IPP backend

[zdohnal]

The previous solution for fixing color override didn't work for queue which point to a remote CUPS queue, this remote queue doesn't use IPP Everywhere model and user uses an application which does not sanitize the print options before sending the job (meaning options contain two different values for color setting - one from ColorModel and the other from print-color-mode).

I've found this on Fedora ( https://bugzilla.redhat.com/show_bug.cgi?id=1985917 ), where user prints from Okular to local driverless queue created by cups-browsed and this queue points to remote CUPS server where the printer is installed with classic driver.