Bump version

Author: madeye

mobile/build.gradle

@@ -21,8 +21,8 @@ android {
         applicationId "com.github.shadowsocks"
         minSdkVersion rootProject.minSdkVersion
         targetSdkVersion rootProject.sdkVersion
-        versionCode 4050600
-        versionName "4.5.6"
+        versionCode 4050700
+        versionName "4.5.7"
         testApplicationId "com.github.shadowsocks.test"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         resConfigs "fa", "fr", "ja", "ko", "ru", "zh-rCN", "zh-rTW"