Fix pipeline badge.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

README.rst

@@ -27,7 +27,7 @@ Status
      :target: https://pyup.io/repos/github/geomultisens/gms_preprocessing/
      :alt: Updates
 
-.. image:: https://gitext.gfz-potsdam.de/geomultisens/gms_preprocessing/badges/master/build.svg
+.. image:: https://gitext.gfz-potsdam.de/geomultisens/gms_preprocessing/badges/master/pipeline.svg
         :target: https://gitext.gfz-potsdam.de/geomultisens/gms_preprocessing/commits/master
 .. image:: https://gitext.gfz-potsdam.de/geomultisens/gms_preprocessing/badges/master/coverage.svg
         :target: http://geomultisens.gitext.gfz-potsdam.de/gms_preprocessing/coverage/