Double slash in svtav1 build script path

[Aleksid1]

In the svtav1 build script there is a double slash in the path (//Build/linux):

download "https://gitlab.com/AOMediaCodec/SVT-AV1/-/archive/v$CURRENT_PACKAGE_VERSION/SVT-AV1-v$CURRENT_PACKAGE_VERSION.tar.gz" "svtav1-$CURRENT_PACKAGE_VERSION.tar.gz"
  cd "${PACKAGES}"/svtav1-$CURRENT_PACKAGE_VERSION//Build/linux || exit

v1.5.9