configure: Don't build python or perl plugin when plugins are disabled

configure.ac

@@ -226,6 +226,8 @@ dnl ** PERL *************************************************************
 dnl *********************************************************************
 
 if test "$perl" = yes; then
+	AC_MSG_CHECKING(for plugin interface used by Perl)
+	if test "$plugin" = yes; then
 		AC_PATH_PROG(perlpath, perl)
 		AC_MSG_CHECKING(for Perl compile flags)
 		PERL_CFLAGS=`$perlpath -MExtUtils::Embed -e ccopts 2>/dev/null`
@@ -251,7 +253,7 @@ if test "$perl" = yes; then
 				CFLAGS="$PERL_CFLAGS"
 				LDFLAGS="$PERL_LDFLAGS"
 				AC_TRY_LINK([#include <EXTERN.h>
-#include <perl.h>], [], perl_is_usable=yes, perl_is_usable=no)
+	#include <perl.h>], [], perl_is_usable=yes, perl_is_usable=no)
 				CFLAGS="$original_cflags"
 				LDFLAGS="$original_ldflags"
 				if test x$perl_is_usable = xno ; then
@@ -273,6 +275,10 @@ if test "$perl" = yes; then
 				perl=no
 			fi
 		fi
+	else
+		AC_MSG_RESULT([plugins are disabled, use the --enable-plugin option for Perl])
+		perl=no
+	fi
 fi
 
 dnl *********************************************************************
@@ -280,6 +286,8 @@ dnl ** PYTHON ***********************************************************
 dnl *********************************************************************
 
 if test "x$python" != xno ; then
+	AC_MSG_CHECKING(for plugin interface used by Python)
+	if test "$plugin" = yes; then
 		case $python in
 			dnl set python2 default here
 			python2)
@@ -302,6 +310,10 @@ if test "x$python" != xno ; then
 		AC_MSG_CHECKING(Python version)
 		AC_MSG_RESULT($PY_VER)
 		python="python-${PY_VER}"
+	else
+		AC_MSG_RESULT([plugins are disabled, use the --enable-plugin option for Python])
+		python=no
+	fi
 fi
 
 dnl *********************************************************************