lua: fix WPA cipher reporting

lua: fix WPA cipher reporting

Use the same logic as the command line interface for reporting the used WPA
ciphers. Instead of printing the intersection of pairwise and group ciphers,
report both group and pairwise ciphers.

This fixes a case where a connection which uses CCMP for pairwise and TKIP
as groupwise cipher is getting reported as using the NONE cipher.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>