w3m: Depends on libbsd and zlib for Linuxbrew
w3m: Depends on libbsd and zlib for Linuxbrew

Fixes Linuxbrew/homebrew-core#1199.
Closes Linuxbrew/homebrew-core#1200.

Signed-off-by: Shaun Jackman <b580dab3251a9622aba3803114310c23fdb42900@gmail.com>

LinuxbrewTestBot/homebrew-core,rwhogg/homebrew-core,LinuxbrewTestBot/homebrew-core,Linuxbrew/homebrew-core,rwhogg/homebrew-core,Linuxbrew/homebrew-core,maxim-belkin/homebrew-core,maxim-belkin/homebrew-core