Add missing && in docker file.

docker/Dockerfile

@@ -1,7 +1,7 @@
 FROM multiarch/alpine:${TARGETARCH}${TARGETVARIANT}-latest-stable AS build
 RUN apk add --no-cache alpine-sdk gcc linux-headers librtlsdr-dev libxml2-dev cmake libusb-dev bash
 RUN git clone https://github.com/wmbusmeters/wmbusmeters.git && \
-    git clone https://github.com/weetmuts/rtl-wmbus.git \
+    git clone https://github.com/weetmuts/rtl-wmbus.git && \
     git clone https://github.com/merbanan/rtl_433.git
 WORKDIR /wmbusmeters
 RUN make