build all in docker

cordova/makefile.am

@@ -19,13 +19,13 @@ ${ANDROID_SRC}:
 	    ( cp -r "@srcdir@/$${file}" "$${file}" && \
 	      chmod -R u+w "$${file}" ); \
 	done
-	if [ "$$(whoami)" != "root" ]; then \
+	if [ "$$(whoami 2> /dev/null)" != "root" ]; then \
 	  ${CORDOVA} plugin add https://github.com/katzer/cordova-plugin-background-mode.git; \
 	  ${CORDOVA} build --debug || ${CORDOVA} build --debug; \
 	fi
 
 ${ANDROID}: ${ANDROID_SRC}
-	if [ "$$(whoami)" != "root" ]; then \
+	if [ "$$(whoami 2> /dev/null)" != "root" ]; then \
 	  cp $< $@; \
 	fi