Bump up version number to 1.2.4-DEV
Bump up version number to 1.2.4-DEV

tatsuhiro-t/spdylay,ahnan4arch/spdylay,tatsuhiro-t/spdylay,mixianghang/spdylay,tatsuhiro-t/spdylay,tatsuhiro-t/spdylay,mixianghang/spdylay,tatsuhiro-t/spdylay,mixianghang/spdylay,ahnan4arch/spdylay,ahnan4arch/spdylay,mixianghang/spdylay,mixianghang/spdylay,ahnan4arch/spdylay,ahnan4arch/spdylay