ui: change Licence into License

In the about fragment, the Licence word is changed into License.
For consistency, the variables' name are modified too.

Change-Id: Ic2b2eeda2800b38ff5f78b96e9cb6d5441c00035
Tuleap: #1420
diff --git a/ring-android/app/src/main/res/values-pl/strings.xml b/ring-android/app/src/main/res/values-pl/strings.xml
index 6ac37e8..42c8a6f 100644
--- a/ring-android/app/src/main/res/values-pl/strings.xml
+++ b/ring-android/app/src/main/res/values-pl/strings.xml
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='UTF-8'?>
 <resources>
-  <string name="section_licence">Licencja</string>
+  <string name="section_license">Licencja</string>
   <string name="sponsor_section">Ring jest wolnym oprogramowaniem stworzonym przez</string>
   <string name="copyright_section">Prawa autorskie</string>
   <string name="contribute_section">WspóĹ‚pracuj</string>