Fixed tagging.

.drone.yml

@@ -38,7 +38,7 @@ steps:
       password:
         from_secret: registry_password
       repo: registry.thegibsonhome.net/protonmail-bridge
-      tags: ${DRONE_COMMIT}
+      tags: ${DRONE_TAG}
 trigger:
   event:
     - tag

Dockerfile

@@ -12,7 +12,7 @@ WORKDIR /usr/src
 ARG TAG
 RUN git clone https://github.com/ProtonMail/proton-bridge.git proton-bridge \
     && cd proton-bridge \
-    && if [ -n "$TAG" ]; then git checkout tags/$TAG; fi \
+    && if [ -n "$TAG" ]; then echo "Using tags/$TAG..."; git checkout tags/$TAG; fi \
     && make build-nogui
 
 # Create a container for the ProtonMail Bridge.