[glib] glib-mkenums: Don't use FileNotFoundError, it's Python 3 only.

[Christoph Reiter <creiter src gnome org>]

commit d88d1ba7e844b5493a53dfcdba77d4df3ea1684d
Author: Christoph Reiter <creiter src gnome org>
Date:   Wed Jul 19 11:49:04 2017 +0200

    glib-mkenums: Don't use FileNotFoundError, it's Python 3 only.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=785113

 gobject/glib-mkenums.in |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/gobject/glib-mkenums.in b/gobject/glib-mkenums.in
index e22b317..653a769 100755
--- a/gobject/glib-mkenums.in
+++ b/gobject/glib-mkenums.in
@@ -15,6 +15,7 @@ import re
 import sys
 import tempfile
 import io
+import errno
 
 VERSION_STR = '''glib-mkenums version @VERSION@
 glib-genmarshal comes with ABSOLUTELY NO WARRANTY.
@@ -399,9 +400,11 @@ def process_file(curfilename):
 
     try:
         curfile = io.open(curfilename, encoding="utf-8")
-    except FileNotFoundError:
-        print_warning('No file "{}" found.'.format(curfilename))
-        return
+    except IOError as e:
+        if e.errno == errno.ENOENT:
+            print_warning('No file "{}" found.'.format(curfilename))
+            return
+        raise
 
     while True:
         line = curfile.readline()