Merge branch 'binary-preserve-assert' into 'master'

Preserve Python assert statements in binary build

Closes #432

See merge request !935

Dockerfile.binary

@@ -52,6 +52,7 @@ RUN find /usr/share/arkindex/*/management -name '*.py' -not -name '__init__.py'
 RUN find /usr/share/arkindex /usr/share/ponos -type d -name tests | xargs rm -rf
 
 # Compile all our python source code
+# Do not use the -O or -OO python flags here as it removes assert statements (see backend#432)
 RUN python -m nuitka \
       --nofollow-imports \
       --include-package=arkindex \
@@ -59,7 +60,6 @@ RUN python -m nuitka \
       --include-package=ponos \
       --include-package=transkribus \
       --show-progress \
-      --python-flag=-OO \
       --lto \
       --output-dir=/build \
       arkindex/manage.py