Fix rate display disappearing in StatusPreference

It turns out that `onCreateView` gets called every time `setSummary` is invoked, and thus restoring texts for `TextView` is mandatory.

src/main/res/values-zh/strings.xml

@@ -116,6 +116,5 @@
   <!-- status -->
   <string name="sent">发送:</string>
   <string name="received">接收:</string>
-  <string name="check_connectivity">检查网络连接</string>
 
 </resources>

src/main/res/values/strings.xml

@@ -124,5 +124,4 @@
   <!-- status -->
   <string name="sent">Sent:</string>
   <string name="received">Received:</string>
-  <string name="check_connectivity">Check Connectivity</string>
 </resources>

src/main/res/xml/pref_all.xml

@@ -10,7 +10,7 @@
 
         <com.github.shadowsocks.preferences.StatusPreference
                 android:key="stat"
-                android:summary="@string/check_connectivity"
+                android:summary="@string/connection_test_pending"
                 android:title="@string/stat"/>
 
     </PreferenceCategory>