fix string

Change-Id: I5e598c15e2ebb2591ae29acf92346131d8d07a4a

ring-android/app/src/main/res/values/strings.xml

@@ -292,7 +292,7 @@ along with this program; if not, write to the Free Software
     <string name="refuse">Refuse</string>
     <string name="block">Block</string>
     <string name="contact_request_title">New contact request</string>
-    <string name="contact_request_msg">You have %1$s contact requests</string>
+    <string name="contact_request_msg">You have %1$d contact requests</string>
     <string name="contact_request_account">For %1$s</string>
     <string name="no_requests">You have no contact requests</string>
     <string name="message_contact_not_trusted_yet">%s is not in your contacts yet.\nDo you accept or refuse this contact request?</string>