Remove unsupported error for aarch64 Linux (#414)

While SignalWire doesn't have aarch64 debs of FreeSWITCH, PostgreSQL.org
and sury.org have debs of PgSQL & PHP for aarch64, respectively.
Compiling FreeSWITCH from source works cleanly on aarch64, tested on
both Armbian and stock Debian. So might as well remove the unsupported.

While we're add it, let's parallelize the makes, as it's dreadfully slow
on most SBCs without it

debian/resources/environment.sh

@@ -69,7 +69,6 @@ if [ .$cpu_architecture = .'arm' ]; then
 	if [ .$os_mode = .'32' ]; then
 		verbose "Correct CPU and Operating System detected, using the ARM repo"
 	elif [ .$os_mode = .'64' ]; then
-		error "You are using a 64bit arm OS this is unsupported"
 		switch_source=true
 		switch_package=false
 	else