Remove -Werror from build flags
Remove -Werror from build flags

Issue #32 (gcc 4.8.4, Qt 5.2.1 in Mint) -Werror may cause the build
to fail due to -Winconsistent-missing-override.

equalsraf/neovim-qt,ngkaho1234/neovim-qt,Pireax/neovim-qt,Pireax/neovim-qt,ngkaho1234/neovim-qt,equalsraf/neovim-qt,equalsraf/neovim-qt,ngkaho1234/neovim-qt,equalsraf/neovim-qt,Pireax/neovim-qt