[pitivi] render: Fix tooltip text

[Alexandru Băluț <alexbalut src gnome org>]

commit 08f3e0ff0ab9bcdb72441b81ce68ad909eb2bde3
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Tue Jul 19 14:33:27 2016 +0200

    render: Fix tooltip text
    
    Reviewed-by: Thibault Saunier <tsaunier gnome org>
    Differential Revision: https://phabricator.freedesktop.org/D1176

 data/ui/renderingdialog.ui |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/ui/renderingdialog.ui b/data/ui/renderingdialog.ui
index ba974f6..d3338d5 100644
--- a/data/ui/renderingdialog.ui
+++ b/data/ui/renderingdialog.ui
@@ -757,7 +757,7 @@
                     <property name="receives_default">False</property>
                     <property name="tooltip_markup" translatable="yes">Use proxy files if they are available 
and the source asset media format is not officially supported.
 
-This option is a good trade of between quality of the rendered video and stability.</property>
+This option is a good trade-off between quality of the rendered video and stability.</property>
                     <property name="xalign">0.05000000074505806</property>
                     <property name="yalign">0</property>
                     <property name="draw_indicator">True</property>