fix compiler warning
fix compiler warning

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