Fixed warnings in run-broker.sh

test/run-broker.sh

@@ -1,3 +1,8 @@
 #!/bin/bash
 
-docker run -it --rm --user $(echo $UID) --name mosquitto -p 8883:8883 -v $(pwd)/broker-config:/mosquitto/config eclipse-mosquitto
+docker run -it --rm \
+    --user "$UID" \
+    -p 8883:8883 \
+    -v "$(pwd)/broker-config:/mosquitto/config" \
+    --name mosquitto \
+    eclipse-mosquitto