docker windows build: fix missing translations

contrib/build-wine/build-electrum-git.sh

@@ -45,6 +45,10 @@ VERSION=`git describe --tags --dirty`
 echo "Last commit: $VERSION"
 
 pushd ./contrib/deterministic-build/electrum-locale
+if ! which msgfmt > /dev/null 2>&1; then
+    echo "Please install gettext"
+    exit 1
+fi
 for i in ./locale/*; do
     dir=$i/LC_MESSAGES
     mkdir -p $dir

contrib/build-wine/docker/Dockerfile

@@ -23,6 +23,7 @@ RUN dpkg --add-architecture i386 && \
         autotools-dev=20180224.1 \
         autoconf=2.69-11 \
         libtool=2.4.6-2 \
+        gettext=0.19.8.1-6 \
         && \
     rm -rf /var/lib/apt/lists/* && \
     apt-get autoremove -y && \

contrib/build-wine/docker/README.md

@@ -1,7 +1,7 @@
 Deterministic Windows binaries with Docker
 ==========================================
 
-This assumes an Ubuntu host, but it should not be too hard to adopt to another
+This assumes an Ubuntu host, but it should not be too hard to adapt to another
 similar system.
 
 1. Install Docker
@@ -17,7 +17,7 @@ similar system.
 
     ```
     $ cd contrib/build-wine/docker
-    $ PROJECT_ROOT=$(pwd)/../../../
+    $ PROJECT_ROOT=$PWD/../../../
     $ sudo docker build --no-cache -t electrum-wine-builder-img .
     ```