Rename "Local manga" -> "Local source"

app/src/main/res/values/strings.xml

@@ -388,7 +388,7 @@
     <string name="no_more_results">No more results</string>
     <string name="no_results_found">No results found</string>
     <string name="http_error_hint">Check website in WebView</string>
-    <string name="local_source">Local manga</string>
+    <string name="local_source">Local source</string>
     <string name="other_source">Other</string>
     <string name="pinned_sources">Pinned</string>
     <string name="invalid_combination">Default can\'t be selected with other categories</string>