Supported x32 architecture.

[vincenzopalazzo]

On my Raspberry pi 3b I received the following error:

➜  ~ lightningd --disable-plugin bcli --daemon
➜  ~ panic: unaligned 64-bit atomic operation

goroutine 29 [running]:
runtime/internal/atomic.panicUnaligned()
	/home/pi/compilers/go/src/runtime/internal/atomic/unaligned.go:8 +0x24
runtime/internal/atomic.Xadd64(0x1cb637c, 0x1)
	/home/pi/compilers/go/src/runtime/internal/atomic/atomic_arm.s:256 +0x14
github.com/niftynei/glightning/jrpc2.(*Client).NextId(...)
	/home/pi/github/go-metrics-reported/vendor/github.com/niftynei/glightning/jrpc2/client.go:229
github.com/niftynei/glightning/jrpc2.(*Client).Request(0x1cb6360, {0x279d6c, 0x3c2db4}, {0x207010, 0x1e0e080})
	/home/pi/github/go-metrics-reported/vendor/github.com/niftynei/glightning/jrpc2/client.go:166 +0x40
github.com/niftynei/glightning/glightning.(*Lightning).GetInfo(...)
	/home/pi/github/go-metrics-reported/vendor/github.com/niftynei/glightning/glightning/lightning.go:1060
github.com/OpenLNMetrics/go-metrics-reported/internal/plugin.(*MetricOne).OnInit(0x1c6a050, 0x1c988d8)
	/home/pi/github/go-metrics-reported/internal/plugin/metrics_one.go:307 +0x50
github.com/OpenLNMetrics/go-metrics-reported/internal/plugin.(*MetricsPlugin).RegisterOneTimeEvt.func1.1(0x3b1350, {0x27d870, 0x1c6a050})
	/home/pi/github/go-metrics-reported/internal/plugin/plugin.go:118 +0x30
created by github.com/OpenLNMetrics/go-metrics-reported/internal/plugin.(*MetricsPlugin).RegisterOneTimeEvt.func1
	/home/pi/github/go-metrics-reported/internal/plugin/plugin.go:117 +0xcc

This PR will fix it, at least it includes a workaround.