man: fix tcpconnect man page
man: fix tcpconnect man page

Add -u and -U options to the synopsis.
Move their description frome the example to the description section.
Add a description to --mntnsmap option.

iovisor/bcc,tuxology/bcc,iovisor/bcc,tuxology/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc,tuxology/bcc,tuxology/bcc,tuxology/bcc,brendangregg/bcc,iovisor/bcc,brendangregg/bcc,brendangregg/bcc