Update docker file

Dockerfile

@@ -23,6 +23,9 @@ RUN wget https://github.com/FluidSynth/fluidsynth/archive/refs/tags/v2.3.3.tar.g
     cd ../../ && \
     rm -rf fluidsynth-2.3.3 v2.3.3.tar.gz
 
+ENV LD_LIBRARY_PATH=/usr/local/lib:${LD_LIBRARY_PATH}
+RUN ldconfig
+
 RUN pip3 install --no-cache-dir --upgrade -r /code/requirements.txt
 
 # Set up a new user named "user" with user ID 1000