CONFIGURE: Check for python module setuptools

It is required for installation of python modules therefore
it should be checked at aonfigure time.

  GEN      ipasetup.py
make[3]: Leaving directory `/workdir/freeipa'
cd .; /usr/bin/python setup.py \
        "--verbose" \
        build \
        --build-base "/workdir/freeipa/ipaclient/build"
Traceback (most recent call last):
  File "setup.py", line 29, in <module>
    from ipasetup import ipasetup  # noqa: E402
  File "/workdir/freeipa/ipasetup.py", line 20, in <module>
    from setuptools.command.build_py import build_py as setuptools_build_py
ImportError: No module named setuptools.command.build_py

configure.ac

@@ -121,6 +121,15 @@ if test "x$PYTHON" = "x" ; then
   AC_MSG_ERROR([Python not found])
 fi
 
+AC_MSG_CHECKING($(basename $PYTHON) module setuptools )
+$PYTHON -c "import setuptools" 2>/dev/null
+if test $? -eq 0; then
+    AC_MSG_RESULT([yes])
+else
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([$PYTHON module setuptools is required for installation])
+fi
+
 dnl ---------------------------------------------------------------------------
 dnl Check for ndr_krb5pac and other samba libraries
 dnl ---------------------------------------------------------------------------