strip objects on native appimage and debian builds (#1095)
strip objects on native appimage and debian builds (#1095)

* strip objects on native debian builds, do not build dropbear on unsupported platforms
* strip appImage too
Frenzie/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,koreader/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,NiLuJe/koreader-base,NiLuJe/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,Frenzie/koreader-base,koreader/koreader-base