Removing matomo url from build config.

.github/CONTRIBUTING.md

@@ -46,27 +46,3 @@ Always check if the web version of your instance is working.
 I won't provide any selfoss instance url. If you want to help, but to not have one, you'll have to install one, and use it.
 
 All the details to need are [here](https://selfoss.aditu.de/).
-
-# Build the project
-
-You can directly import this project into IntellIJ/Android Studio.
-
-You'll have to:
-
-- Define some parameters either in `~/.gradle/gradle.properties` or as gradle parameters (see the examples)
-
-    - matomoUrl and matomoSite: url and siteId for a matomo instance
-
-### Examples:
-#### Inside ~/.gradle/gradle.properties
-
-```
-matomoUrl="URL" # It can be empty.
-matomoSite="1" # It can be empty, but needs to be an integer
-```
-
-#### As gradle parameters
-
-```
-./gradlew .... -P matomoUrl="URL" -P matomoSite="1"
-```