Added build entry for Wordpress 2.6.3 (98)

Remomve libs/MixPanelAPI.jar & patched out Mixpanel related logic, since
it is used to gather analytics data, see:
https://mixpanel.com/android-analytics/

metadata/org.wordpress.android.txt

@@ -127,6 +127,12 @@ Build:2.6.1,96
     init=cp local.properties-example local.properties
     gradle=yes
 
+Build:2.6.3,98
+    commit=2.6.3
+    init=cp local.properties-example local.properties;rm libs/MixpanelAPI.jar
+    prebuild=sed -e '/[Mm]ixpanel/ d' -i build.gradle src/org/wordpress/android/util/WPMobileStatsUtil.java
+    gradle=yes
+
 Auto Update Mode:None
 Update Check Mode:Tags
 Current Version:2.6.3