mozilla.debian.net: minor corrections

[Bob Bib]

Hello Mozilla Maintainers,

http://mozilla.debian.net/ webpage seems to contain some little typos:
"$ apt-get update ...", "$ apt-get install ..."
instead of
"# apt-get update ...", "# apt-get install ..."

AFAIK, 'apt-get' should be run with root privileges to make any changes;
BTW, "$ gpg --check-sigs ..." works for an ordinary user, and so is OK :)