[gtk-osx] Revert cairomm to 1.13.1.

[John Ralls <jralls src gnome org>]

commit 2f64c8d2b8b907b34bdb35756571e27615c82173
Author: John Ralls <jralls ceridwen us>
Date:   Mon Feb 4 21:34:57 2019 -0800

    Revert cairomm to 1.13.1.
    
    cairomm 1.15 requires libsigc++3 which doesn't have a stable release.
    
    Closes: https://gitlab.gnome.org/GNOME/gtk-osx/issues/3

 modulesets-stable/gtk-osx-gtkmm.modules | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/modulesets-stable/gtk-osx-gtkmm.modules b/modulesets-stable/gtk-osx-gtkmm.modules
index 5cd9b74..c572d8f 100644
--- a/modulesets-stable/gtk-osx-gtkmm.modules
+++ b/modulesets-stable/gtk-osx-gtkmm.modules
@@ -26,8 +26,8 @@
   </autotools>
 
   <autotools id="cairomm" autogen-sh="configure">
-    <branch module="cairomm-1.15.5.tar.gz" version="1.15.5"
-           hash="sha1:f95ae92551ea4d0a9214e45834ae9806dfee9e3d"
+    <branch module="cairomm-1.13.1.tar.gz" version="1.13.1"
+           hash="sha1:63cd9eab40686f368a8edd3e6912ac18b3048ecf"
             repo="cairographics">
       <patch 
file="https://gitlab.gnome.org/GNOME/gtk-osx/raw/master/patches/cairomm-Bug-100894-Cairomm-compile-failure-if-no-cairo-ft.patch";
 strip="1"/>
     </branch>