ngxpagespeed.com configuration: fix /install (#1444)
ngxpagespeed.com configuration: fix /install (#1444)

ngxpagespeed.com/install serves a redirect to build_ngx_pagespeed.sh on github.  Now that we develop on master and trunk-tracking is gone, fix it to point at master.

Already fixed (manually) on the live site.
VersoBit/mod_pagespeed,hashashin/src,pagespeed/mod_pagespeed,VersoBit/mod_pagespeed,pagespeed/mod_pagespeed,VersoBit/mod_pagespeed,hashashin/src,pagespeed/mod_pagespeed,VersoBit/mod_pagespeed,pagespeed/mod_pagespeed,pagespeed/mod_pagespeed,pagespeed/mod_pagespeed,VersoBit/mod_pagespeed,pagespeed/mod_pagespeed,hashashin/src,hashashin/src,VersoBit/mod_pagespeed,hashashin/src,hashashin/src,VersoBit/mod_pagespeed,hashashin/src,hashashin/src