Fix EXPOSE with protocol

[zemanlx]

Right now there is only supported

EXPOSE <port>  [<port> ...]

where port is integer, but in reference EXPOSE is defined as

EXPOSE <port> [<port>/<protocol>...]

The EXPOSE instruction informs Docker that the container listens on the specified network ports at runtime. You can specify whether the port listens on TCP or UDP, and the default is TCP if the protocol is not specified.