Fixed: Connection timeout with pgp.mit.edu PGP key server (replaced by keyserver.ubuntu.com)

Quote from i-MSCP Github (hotfixes)

Code

1. Fixed: Connection timeout with pgp.mit.edu PGP key server (replaced by keyserver.ubuntu.com)
2. [ci skip]

Source: https://github.com/i-MSCP/imsc…46e0b3df36add084504ca829a