python-matplotlib: Update to 2.1.2

mingw-w64-python-matplotlib/setup.py.patch

@@ -1,6 +1,6 @@
---- matplotlib-2.0.0/setup.py.orig	2017-02-15 14:08:45 +0900
-+++ matplotlib-2.0.0/setup.py	2017-02-15 14:09:26 +0900
-@@ -103,7 +103,7 @@
+--- matplotlib-2.1.2/setup.py.orig	2018-01-18 07:21:34.000000000 +0300
++++ matplotlib-2.1.2/setup.py	2018-01-25 08:35:39.807755700 +0300
+@@ -102,7 +102,7 @@
      setupext.BackendGtk3Agg(),
      setupext.BackendGtk3Cairo(),
      setupext.BackendGtkAgg(),