Fix apt install section (broke by bd8ebfc)

Author: andy5995

make-appimage.sh

@@ -47,6 +47,7 @@ fi
 cd "$WORKSPACE"
 
 sudo DEBIAN_FRONTEND=noninteractive -i sh -c "apt update && apt -y upgrade &&
+  apt install -y
     libboost-dev
     libboost-filesystem-dev
     libboost-system-dev