guile

[Aaron Laws]

I'm using archlinux (https://distrowatch.com/table.php?distribution=arch).
It supplies guile 2.0 and guile 2.2 at the same time as /usr/bin/guile2.0
and /usr/bin/guile, respectively. When I build gnucash, I get errors since
I'm using guile2.2. Perhaps the fix is as simple as:

FIND_PROGRAM (GUILE_EXECUTABLE guile2.0 guile)

(and an analogous change for guild) in CMakeLists.txt ? If someone else
would make this change and confirm that the system can find "guile" as
well, that would be helpful.