[aur-general] Remove request:airdrop-ng, airgraph-ng and aircrack-ptw

[郑文辉(Techlive Zheng)]

airdrop-ng and airgraph-ng is duplicated with aircrack-ng-scripts in community.

aircrack-ptw has been included into aircrack-ng since version 0.9, and
the source link in PKGBUILD has down.

airdrop-ng:https://aur.archlinux.org/packages.php?ID=41584
airgraph-ng:https://aur.archlinux.org/packages.php?ID=44546
aircrack-ptw:https://aur.archlinux.org/packages.php?ID=18331