Bring back external changelog

app/build.gradle

@@ -139,6 +139,7 @@ android {
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "false"
             buildConfigField "boolean", "AMAZON_RELEASE", "false"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/donate/\""
+            buildConfigField "String", "CHANGELOG", "\"https://github.com/M66B/FairEmail/releases/\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"https://api.github.com/repos/M66B/FairEmail/releases/latest\""
             buildConfigField "String", "GITHUB_LATEST_URI", "\"https://github.com/M66B/FairEmail/releases\""
             buildConfigField "String", "GRAVATAR_URI", "\"https://www.gravatar.com/avatar/\""
@@ -150,6 +151,7 @@ android {
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "false"
             buildConfigField "boolean", "AMAZON_RELEASE", "false"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/donate/\""
+            buildConfigField "String", "CHANGELOG", "\"https://github.com/M66B/FairEmail/releases/\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"https://api.github.com/repos/M66B/FairEmail/releases/latest\""
             buildConfigField "String", "GITHUB_LATEST_URI", "\"https://github.com/M66B/FairEmail/releases\""
             buildConfigField "String", "GRAVATAR_URI", "\"https://www.gravatar.com/avatar/\""
@@ -162,6 +164,7 @@ android {
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "true"
             buildConfigField "boolean", "AMAZON_RELEASE", "false"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/#pro\""
+            buildConfigField "String", "CHANGELOG", "\"\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"\""
             buildConfigField "String", "GITHUB_LATEST_URI", "\"\""
             buildConfigField "String", "GRAVATAR_URI", "\"\""

app/src/main/java/eu/faircode/email/FragmentAbout.java

@@ -87,7 +87,7 @@ public class FragmentAbout extends FragmentBase {
                 if (BuildConfig.PLAY_STORE_RELEASE)
                     Helper.view(v.getContext(), Helper.getIntentRate(v.getContext()));
                 else
-                    onMenuChangelog();
+                    Helper.view(v.getContext(), Uri.parse(BuildConfig.CHANGELOG), false);
             }
         });