configure: request libmypaint version 1.3.0 or higher.

libmypaint just got ported to autotools, which makes GIMP again easily
built on all kind of platforms. There is no need to rely on older
versions of this library which would only give us headaches.

configure.ac

@@ -67,7 +67,7 @@ m4_define([poppler_required_version], [0.12.4])
 m4_define([poppler_data_required_version], [0.4.7])
 m4_define([libgudev_required_version], [167])
 m4_define([gexiv2_required_version], [0.6.1])
-m4_define([libmypaint_required_version], [1.1])
+m4_define([libmypaint_required_version], [1.3.0])
 m4_define([lcms_required_version], [2.6])
 m4_define([libpng_required_version], [1.2.37])
 m4_define([liblzma_required_version], [5.0.0])