matrix-static does not start if initial request to client/r0/publicRooms times out

[michaelkaye]

When starting, matrix-static can panic mid-startup when it's doing it's initial sync of publicRooms:

panic: Get <<REDACTED - client/r0/publicRooms url with access token>>: net/http: request canceled (Client.Timeout exceeded while awaiting headers)

goroutine 1 [running]:
github.com/t3chguy/matrix-static/mxclient.(*Client).NewWorldReadableRooms(0xc4202d90a0, 0xd)
        /home/matrixstatic/matrix-static/src/github.com/t3chguy/matrix-static/mxclient/public-rooms.go:53 +0x8d
main.main()
        /home/matrixstatic/matrix-static/src/github.com/t3chguy/matrix-static/matrix-static.go:93 +0x368
error: Forever detected script exited with code: 2

This isn't particularly fatal, we can just restart matrix-static until it completes, but adding a longer timeout may be useful here.