Update Dockerfile

windows/Dockerfile

@@ -9,7 +9,7 @@ apt -y install iputils-ping nano \
     libtool-bin libltdl-dev libssl-dev libxml-parser-perl make \
     openssl p7zip-full patch perl pkg-config python ruby scons \
     sed unzip wget xz-utils \
-    g++-multilib libc6-dev-i386 &&
+    g++-multilib libc6-dev-i386 && \
 apt -y autoremove && \
 apt -y autoclean && \
 apt -y clean && \
@@ -17,6 +17,6 @@ cd /opt && \
 git clone https://github.com/mxe/mxe.git && \
 cd mxe && \
 make -j $(($(grep -c ^processor /proc/cpuinfo 2>/dev/null || 1)+2)) MXE_TARGETS='i686-w64-mingw32.static' qtbase && \
-/opt/mxe/usr/bin/i686-w64-mingw32.static-qmake-qt5 --version
+/opt/mxe/usr/bin/i686-w64-mingw32.static-qmake-qt5 --version && \
 exit 0
 ENV PATH="${PATH}:/opt/mxe/usr/bin"