Add mkmf.log to gitignore.
Add mkmf.log to gitignore.

pkmiec/passenger,pkmiec/passenger,openSUSE/passenger,kewaunited/passenger,fabiokung/passenger-debian,kewaunited/passenger,phusion/passenger,openSUSE/passenger,gravitystorm/passenger,pkmiec/passenger,fabiokung/passenger-debian,clemensg/passenger,antek-drzewiecki/passenger,gravitystorm/passenger,bf4/passenger,antek-drzewiecki/passenger,gravitystorm/passenger,kewaunited/passenger,clemensg/passenger,antek-drzewiecki/passenger,bf4/passenger,bf4/passenger,fabiokung/passenger-debian,kewaunited/passenger,bf4/passenger,fabiokung/passenger-debian,cgvarela/passenger,erikogan/passenger,antek-drzewiecki/passenger,phusion/passenger,jawj/passenger,erikogan/passenger,cgvarela/passenger,cgvarela/passenger,erikogan/passenger,fabiokung/passenger-debian,clemensg/passenger,fabiokung/passenger-debian,pkmiec/passenger,openSUSE/passenger,kewaunited/passenger,pkmiec/passenger,antek-drzewiecki/passenger,phusion/passenger,antek-drzewiecki/passenger,openSUSE/passenger,kewaunited/passenger,jawj/passenger,bf4/passenger,bf4/passenger,openSUSE/passenger,kewaunited/passenger,erikogan/passenger,pkmiec/passenger,phusion/passenger,cgvarela/passenger,clemensg/passenger,kewaunited/passenger,cgvarela/passenger,jawj/passenger,gravitystorm/passenger,antek-drzewiecki/passenger,antek-drzewiecki/passenger,jawj/passenger,clemensg/passenger,cgvarela/passenger,cgvarela/passenger,phusion/passenger,openSUSE/passenger,phusion/passenger,clemensg/passenger,jawj/passenger,phusion/passenger,clemensg/passenger,gravitystorm/passenger,erikogan/passenger,jawj/passenger,jawj/passenger,gravitystorm/passenger,cgvarela/passenger,erikogan/passenger,bf4/passenger,phusion/passenger,pkmiec/passenger,clemensg/passenger