CONTRIBUTING.md: Fix clone URL (#177)

ramthi · Oberon00 · commit 9dda706624ec · 2019-09-30T16:06:43.000+02:00
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -37,7 +37,7 @@ pull requests (PRs).
 To create a new PR, fork the project in GitHub and clone the upstream repo:
 
 ```sh
-$ git clone https://https://github.com/open-telemetry/opentelemetry-python.git
+$ git clone https://github.com/open-telemetry/opentelemetry-python.git
 ```
 
 Add your fork as an origin:
