clean up hyper commit help msg
clean up hyper commit help msg

Do not manipuate the displayed default value.
We default to false. Besides, go-flags only use value-name
to generate command line help message and manpage. And
it is ignored for bool option in go-flags generated
help message.

Signed-off-by: Peng Tao <39d8af57313740070ea49547576f55682fe5221a@gmail.com>

hyperhq/hyperd,gao-feng/hyper,laijs/hyperd,bergwolf/hyperd,gao-feng/hyper,hyperhq/hyper,laijs/hyper,gao-feng/hyper,gao-feng/hyper-public,bergwolf/hyperd,feiskyer/hyper,ZJU-SEL/hyper,bergwolf/hyperd,feiskyer/hyper,gnawux/hyper,hyperhq/hyper,laijs/hyper,feiskyer/hyper,hyperhq/hyper,laijs/hyperd,gao-feng/hyper,ZJU-SEL/hyper,hyperhq/hyperd,gnawux/hyper,hyperhq/hyperd,laijs/hyper,laijs/hyper,gao-feng/hyper-public,ZJU-SEL/hyper,hyperhq/hyper,feiskyer/hyper,gnawux/hyper,bergwolf/hyperd,ZJU-SEL/hyper,laijs/hyperd,gao-feng/hyper-public