Revert an upstream commit to enable compiling without external glib2.

Edit the 'disable UI compilation' patch to match the original
upstream commit more closely.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

The purpose of irqbalance is to distribute hardware interrupts across
processors/cores on a multiprocessor/-core system in order to increase
performance.

This initial implementation of the package uses external glib2,
which is a large dependency.
Only the cmd-line tool is compiled and installed.

Run-tested with ipq806x / R7800.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>