configure.ac: a developer checkout may also be detected with git

configure.ac

@@ -1069,7 +1069,7 @@ AC_SUBST(CC_OR_MPICC, $cc_or_mpicc)
 # If the user specifically asks for it, or if we are in a developer checkout, we enable mpi check
 AC_ARG_ENABLE(mpi-check, AC_HELP_STRING([--enable-mpi-check], [Enable execution of MPI testcases]))
 running_mpi_check=no
-if test -d "$srcdir/.svn" ; then
+if test -d "$srcdir/.svn" -o -d "$srcdir/.git" ; then
     running_mpi_check=yes
 fi
 if test x$enable_mpi_check = xyes ; then