[gtk-doc] mkpdf: suppress warning about missing chars

[Stefan Sauer <stefkost src gnome org>]

commit 1abdeaedc3c1f17fc563891810b68b6053caa6bd
Author: Stefan Sauer <ensonic users sf net>
Date:   Tue Mar 21 22:34:05 2017 +0100

    mkpdf: suppress warning about missing chars
    
    There is nothing the user can do here.

 gtkdoc-mkpdf.in |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/gtkdoc-mkpdf.in b/gtkdoc-mkpdf.in
index 19dfc78..58b2ab0 100755
--- a/gtkdoc-mkpdf.in
+++ b/gtkdoc-mkpdf.in
@@ -93,8 +93,14 @@ if dblatex != '':
     pc = subprocess.Popen(dbcmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     (stde, _) = pc.communicate()
     for line in stde.split('\n'):
-        if 'programlisting or screen' not in line and line.strip():
-            print(line)
+        if not line.strip():
+            continue
+        if 'programlisting or screen' in line:
+            continue
+        # This happens when dblatex has no support for some special chars
+        if 'Missing character' in line:
+            continue
+        print(line)
 elif fop != '':
     if options.verbose:
         quiet = '0'