w3m 0.5.3: Fix redefinition of struct file_handle

Fix istream.h:23:8: error: redefinition of 'struct file_handle'
See https://sourceforge.net/p/w3m/patches/62/

Closes Homebrew/linuxbrew#159
Linuxbrew: Xcode.provides_autotools? is false

Closes Homebrew/linuxbrew#167