try different name in variable

Author: phlptp

CMakeLists.txt

@@ -218,7 +218,7 @@ elseif(UNITS_ENABLE_TESTS AND NOT CMAKE_VERSION VERSION_LESS 3.13)
     if(UNITS_BUILD_GTEST)
         if(NOT EXISTS "${PROJECT_SOURCE_DIR}/ThirdParty/googletest/CMakeLists.txt")
             include(updateGitSubmodules)
-            if(${PROJECT_NAME}_ENABLE_SUBMODULE_UPDATE)
+            if(${UNITS_CMAKE_PROJECT_NAME}_ENABLE_SUBMODULE_UPDATE)
                 submod_update(ThirdParty/googletest)
             else()
                 include(FindPkgConfig)