[Ubuntu] Remove workaround for vcpkg

[miketimofeev]

Don't need this workaround anymore – issue fixed in microsoft/vcpkg#10846

[maxim-lobanov]

/azp run ubuntu1604, ubuntu1804

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[miketimofeev]

There is a new error with g++, need to invesitgate

==> azure-arm: CMake Error at cmake/utilities.cmake:6 (message):
==> azure-arm:   The g++ version picked up is too old; please install a newer compiler such
==> azure-arm:   as g++-7.
    azure-arm: -- Configuring incomplete, errors occurred!
    azure-arm: See also "/usr/local/share/vcpkg/toolsrc/build.rel/CMakeFiles/CMakeOutput.log".
==> azure-arm:
==> azure-arm:                       On Ubuntu try the following:
==> azure-arm:                           sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
==> azure-arm:                           sudo apt-get update -y
==> azure-arm:                           sudo apt-get install g++-7 -y
==> azure-arm:                       On CentOS try the following:
==> azure-arm:                           sudo yum install centos-release-scl
==> azure-arm:                           sudo yum install devtoolset-7
==> azure-arm:                           scl enable devtoolset-7 bash
==> azure-arm: Call Stack (most recent call first):
==> azure-arm:   CMakeLists.txt:29 (vcpkg_detect_compiler)
==> azure-arm:
==> azure-arm: