remove erroneous \

docker/Dockerfile

@@ -42,7 +42,7 @@ RUN apk add \
 
 # configure a user
 RUN addgroup -S "$username" \
-    && adduser -S -G "$username" -s /bin/bash "$username" \
+    && adduser -S -G "$username" -s /bin/bash "$username"
     
 # ARG enablesudo="true"
 # RUN if test "$enablesudo"; then true \