Externals Update, master branch (2020.07.08.)

Updated all projects to atlasexternals-2.0.71, with a quick update after yesterday's move (!34283 (merged)) to atlasexternals-2.0.70.

The full list of updates are (atlasexternals@2.0.70...2.0.71):

• Updated to prmon v2.0.0 (thanks to @amete);
• Fixed a capitalisation typo in FindNjets.cmake;
• Fixed the RPM dependency setup of Findfmt.cmake.

The last issue causes the following warning to appear with the latest nightlies when using Projects/WorkDir:

CMake Warning at /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-07T2139/Athena/22.0.16/InstallArea/x86_64-centos7-gcc8-opt/cmake/modules/LCGFunctions.cmake:1131 (find_package):
  By not providing "Findfmt.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "fmt", but
  CMake did not find one.

  Could not find a package configuration file provided by "fmt" with any of
  the following names:

    fmtConfig.cmake
    fmt-config.cmake

  Add the installation prefix of "fmt" to CMAKE_PREFIX_PATH or set "fmt_DIR"
  to a directory containing one of the above files.  If "fmt" provides a
  separate development package or SDK, be sure it has been installed.
Call Stack (most recent call first):
  /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-07T2139/Athena/22.0.16/InstallArea/x86_64-centos7-gcc8-opt/cmake/modules/Findfmt.cmake:11 (lcg_wrap_find_module)
  /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-07T2139/Athena/22.0.16/InstallArea/x86_64-centos7-gcc8-opt/cmake/modules/FindGaudi.cmake:65 (find_package)
  /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-07T2139/Athena/22.0.16/InstallArea/x86_64-centos7-gcc8-opt/cmake/PostConfig.cmake:24 (find_package)
  /cvmfs/atlas-nightlies.cern.ch/repo/sw/master_Athena_x86_64-centos7-gcc8-opt/2020-07-07T2139/Athena/22.0.16/InstallArea/x86_64-centos7-gcc8-opt/cmake/AthenaConfig.cmake:369 (include)
  CMakeLists.txt:40 (find_package)

(I'm a bit surprised that people have not been complaining about this on the mailing lists yet...)