package/avahi: add pygobject support, move to python3

The python support in avahi needs pygobjet to do anything:

Building avahi-python:              no   (You need python, pygobject and python-dbus!)

So add optional support for it.  Python-gobject is only available for
python3, so change the python logic to use python 3.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/avahi/avahi.mk

@@ -40,7 +40,6 @@ AVAHI_CONF_OPTS = \
 	--disable-gtk \
 	--disable-gtk3 \
 	--disable-gdbm \
-	--disable-pygobject \
 	--disable-mono \
 	--disable-monodoc \
 	--disable-stack-protector \
@@ -104,16 +103,16 @@ else
 AVAHI_CONF_OPTS += --disable-glib --disable-gobject
 endif
 
-ifeq ($(BR2_PACKAGE_PYTHON),y)
+ifeq ($(BR2_PACKAGE_PYTHON3),y)
 AVAHI_CONF_ENV += \
-	am_cv_pathless_PYTHON=python \
-	am_cv_python_version=$(PYTHON_VERSION) \
-	am_cv_python_platform=linux2 \
-	am_cv_python_pythondir=/usr/lib/python$(PYTHON_VERSION_MAJOR)/site-packages \
-	am_cv_python_pyexecdir=/usr/lib/python$(PYTHON_VERSION_MAJOR)/site-packages \
+	am_cv_pathless_PYTHON=python3 \
+	am_cv_python_version=$(PYTHON3_VERSION) \
+	am_cv_python_platform=linux5 \
+	am_cv_python_pythondir=/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages \
+	am_cv_python_pyexecdir=/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages \
 	py_cv_mod_socket_=yes
 
-AVAHI_DEPENDENCIES += python
+AVAHI_DEPENDENCIES += python3
 AVAHI_CONF_OPTS += --enable-python
 else
 AVAHI_CONF_OPTS += --disable-python
@@ -127,6 +126,13 @@ else
 AVAHI_CONF_OPTS += --disable-python-dbus
 endif
 
+ifeq ($(BR2_PACKAGE_PYTHON_GOBJECT),y)
+AVAHI_CONF_OPTS += --enable-pygobject
+AVAHI_DEPENDENCIES += python-gobject
+else
+AVAHI_CONF_OPTS += --disable-pygobject
+endif
+
 AVAHI_CONF_ENV += CFLAGS="$(AVAHI_CFLAGS)"
 
 AVAHI_MAKE_OPTS += LIBS=$(TARGET_NLS_LIBS)