SW-658: Correct CMake's finding of Boost's Python libs for Ubuntu 18 again

CMake/FindBoost.cmake

@@ -70,7 +70,7 @@ if("${Boost_FIND_COMPONENTS}" MATCHES "python")
                Boost_FIND_COMPONENTS "${Boost_FIND_COMPONENTS}")
       else(APPLE)
         if(EXISTS "/etc/debian_version")
-            string(REPLACE "python" "python${PYTHON_VERSION_MAJOR}${PYTHON_VERSION_MINOR}" Boost_FIND_COMPONENTS "${Boost_FIND_COMPONENTS}")
+            string(REPLACE "python" "python-py${PYTHON_VERSION_MAJOR}${PYTHON_VERSION_MINOR}" Boost_FIND_COMPONENTS "${Boost_FIND_COMPONENTS}")
         else(EXISTS "/etc/debian_version")
             string(REPLACE "python" "python3" Boost_FIND_COMPONENTS "${Boost_FIND_COMPONENTS}")
         endif(EXISTS "/etc/debian_version")