Remove google play link

Based on your last updates, it seems like google play is completely out
of the question now.

Clover/app/src/main/res/values/private_strings.xml

@@ -5,10 +5,6 @@
         <item>Give a PayPal or Bitcoin donation to the Clover developer</item>
         <item>https://floens.github.io/Clover/#donate</item>
 
-        <item>Rate Clover</item>
-        <item>Rate Clover on Google Play</item>
-        <item>https://play.google.com/store/apps/details?id=org.floens.chan</item>
-
         <item>Find Clover on GitHub</item>
         <item>View the source code and give feedback</item>
         <item>https://github.com/Floens/Clover</item>