Don't enable GCOV by default, make test is not ready for that.

When make test is run with gcov, coverage output files are
created. On the second run, when they are already there,
the server fails to start.

cmake/profile.cmake

 check_library_exists (gcov __gcov_flush  ""  HAVE_GCOV)
 
-if (CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(ENABLE_GCOV_DEFAULT ON)
-else()
-    set(ENABLE_GCOV_DEFAULT OFF)
-endif()
+set(ENABLE_GCOV_DEFAULT OFF)
 option(ENABLE_GCOV "Enable integration with gcov, a code coverage program" ${ENABLE_GCOV_DEFAULT})
 
 if (ENABLE_GCOV)