wifireconnect: wget rather than ping

[macmpi]

You may want to consider using something like below instead of ping here:
wget -q --tries=10 --timeout=20 --spider http://google.com > /dev/null 2>&1.

Indeed in some case ping may have execute rights issues or even be blocked by some ISPs.
It's a fairly commonly used method to check internet availability and proper name resolution; wget is available for any user.

[balbuze]

I upload a new version using wget. But not tested...

[macmpi]

Can't test either (hence I did not originally submit a PR), but confident it should work as I'm using similar thing here.
Hope it helped.