Update com.github.panosx2.brightness.appdata.xml.in

Author: panosx2

data/com.github.panosx2.brightness.appdata.xml.in

@@ -29,7 +29,7 @@
     <category>System</category>
   </categories>
   <releases>
-    <release version="1.4.28" date="2019-05-07" urgency="medium">
+    <release version="1.4.29" date="2019-05-07" urgency="medium">
       <description>
         <ul>
           <li>added auto-save for brightness preferences</li>