[gstreamermm] .gitignore: ignore doxygen autogenerated file

[Marcin Kolny <mkolny src gnome org>]

commit f8b196d9cb35ed58f279606d5765a1c5757b2680
Author: Marcin Kolny <marcin kolny flytronic pl>
Date:   Mon Apr 27 09:36:30 2015 +0200

    .gitignore: ignore doxygen autogenerated file
    
        .gitignore: ignore file containing doxygen css styles.

 .gitignore |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index 3ad2a07..115a140 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,6 +29,7 @@ stamp-h?
 /docs/doc-install.pl
 /docs/doc-postprocess.pl
 /docs/doxygen.css
+/docs/doxygen-extra.css
 /docs/tagfile-to-devhelp2.xsl
 /docs/reference/Doxyfile
 /docs/reference/doxygen.log