configure.ac: revert #19041, we do not want to fail when no C++ compiler is available

configure.ac

@@ -82,10 +82,6 @@ AC_CHECK_PROGS(PROG_STAT,gstat stat)
 AC_CHECK_PROGS(PROG_DATE,gdate date)
 AC_OPENMP
 
-if test x$CXX = x; then
-   AC_MSG_ERROR([No compiler C++ found])
-fi
-
 if test x$enable_perf_debug = xyes; then
     enable_shared=no
 fi