[build] Fixed lpeg built by luarocks not overridden on Android
[build] Fixed lpeg built by luarocks not overridden on Android

NiLuJe/koreader-base,apletnev/koreader-base,houqp/koreader-base,koreader/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,apletnev/koreader-base,NiLuJe/koreader-base,houqp/koreader-base,Frenzie/koreader-base,Frenzie/koreader-base,koreader/koreader-base,koreader/koreader-base,NiLuJe/koreader-base,koreader/koreader-base,houqp/koreader-base,houqp/koreader-base,apletnev/koreader-base,apletnev/koreader-base,NiLuJe/koreader-base