fix png parser bug: 0 size chunk cause strange effect
fix png parser bug: 0 size chunk cause strange effect

Suwmlee/sji-android-screen-capture,koichirok/sji-android-screen-capture,koichirok/sji-android-screen-capture,Suwmlee/sji-android-screen-capture,Suwmlee/sji-android-screen-capture,koichirok/sji-android-screen-capture,Suwmlee/sji-android-screen-capture,Suwmlee/sji-android-screen-capture,koichirok/sji-android-screen-capture,Suwmlee/sji-android-screen-capture,koichirok/sji-android-screen-capture