message: Use tar instead of cpack
diff: @@ -459,10 +459,9 @@ def doBuildAppleDevice(String sdk, String buildType) {
  ONLY_ACTIVE_ARCH=NO
  mkdir -p install/lib
  cp src/realm/${buildType}/librealm.a install/lib
  - xcodebuild -sdk ${sdk}os \\
  - -configuration ${buildType} \\
  - -target package \\
  - ONLY_ACTIVE_ARCH=NO
  + cd install
  + tar -cvzf realm-core-${sdk}os-${version}-${buildType.toLowerCase()}.tar.gz lib include
  + mv *.tar.gz ..
  """
  } finally {
  collectCompilerWarnings('clang', true)
  