wget: add license
wget: add license

Sources:

- https://www.gnu.org/software/wget/

  > GNU Wget is distributed under the GNU General Public License.

- https://git.savannah.gnu.org/cgit/wget.git/tree/README

  > This program is free software; you can redistribute it and/or modify it
  > under the terms of the GNU General Public License as published by the
  > Free Software Foundation; either version 3 of the License,
  > or (at your option) any later version.

adam-moss/homebrew-core,makigumo/homebrew-core,spaam/homebrew-core,nbari/homebrew-core,mbcoguno/homebrew-core,sjackman/homebrew-core,Moisan/homebrew-core,Linuxbrew/homebrew-core,spaam/homebrew-core,jvillard/homebrew-core,jvillard/homebrew-core,nbari/homebrew-core,nandub/homebrew-core,jabenninghoff/homebrew-core,filcab/homebrew-core,JCount/homebrew-core,cblecker/homebrew-core,stgraber/homebrew-core,mfikes/homebrew-core,mfikes/homebrew-core,jvillard/homebrew-core,cblecker/homebrew-core,filcab/homebrew-core,lemzwerg/homebrew-core,dsXLII/homebrew-core,nandub/homebrew-core,stgraber/homebrew-core,mahori/homebrew-core,zyedidia/homebrew-core,mahori/homebrew-core,makigumo/homebrew-core,zyedidia/homebrew-core,chrisfinazzo/homebrew-core,Homebrew/homebrew-core,uyjulian/homebrew-core,lemzwerg/homebrew-core,mbcoguno/homebrew-core,mbcoguno/homebrew-core,sjackman/homebrew-core,adam-moss/homebrew-core,Linuxbrew/homebrew-core,jabenninghoff/homebrew-core,uyjulian/homebrew-core,JCount/homebrew-core,Homebrew/homebrew-core,Moisan/homebrew-core,dsXLII/homebrew-core,chrisfinazzo/homebrew-core