[gnome-robots] Improve punctuation in appdata

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ec71101ebbeb38524e0c745c2f9521dd624c574e
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sat Jan 4 09:06:22 2020 -0600

    Improve punctuation in appdata

 data/org.gnome.Robots.appdata.xml.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/data/org.gnome.Robots.appdata.xml.in b/data/org.gnome.Robots.appdata.xml.in
index b5f3593..a008dcc 100644
--- a/data/org.gnome.Robots.appdata.xml.in
+++ b/data/org.gnome.Robots.appdata.xml.in
@@ -8,7 +8,7 @@
   <summary>Avoid the robots and make them crash into each other</summary>
   <description>
     <p>
-      It is the distant future – the year 2000. Evil robots are trying to kill you.
+      It is the distant future: the year 2000. Evil robots are trying to kill you.
       Avoid the robots or face certain death.
     </p>
     <p>