Bump version to v0.15.11

CHANGELOG.md

 # Silence Changelog
 
+### [0.15.11] - 2018-01-04
+- Fixed persistent crash when downloading some MMS messages
+- Updated translations
+
 ### [0.15.10] - 2017-11-30
 - Fixed crash on some devices when exporting data
 - Added fallback to ROM's emojis
@@ -234,6 +238,7 @@
 - Changed app name
 - Removed non-free libraries
 
+ [0.15.11]: https://github.com/SilenceIM/Silence/compare/v0.15.10...v0.15.11
  [0.15.10]: https://github.com/SilenceIM/Silence/compare/v0.15.9...v0.15.10
  [0.15.9]: https://github.com/SilenceIM/Silence/compare/v0.15.8...v0.15.9
  [0.15.8]: https://github.com/SilenceIM/Silence/compare/v0.15.7...v0.15.8

build.gradle

@@ -141,8 +141,8 @@ android {
     useLibrary 'org.apache.http.legacy'
 
     defaultConfig {
-        versionCode 139
-        versionName "0.15.10"
+        versionCode 140
+        versionName "0.15.11"
 
         minSdkVersion 9
         targetSdkVersion 22