Fix ui dockerfile. (#1909)

Signed-off-by: lkk <33276950+lkk12014402@users.noreply.github.com>
(cherry picked from commit ff66600)

Author: lkk12014402

AgentQnA/ui/docker/Dockerfile

@@ -40,8 +40,7 @@ RUN git config --global user.name "opea" && \
 
 WORKDIR /app/open-webui
 
-RUN git checkout ${WEBUI_VERSION} && \
-    if [ -d patches ] && [ "$(ls -A patches)" ]; then git am /app/patches/*.patch; fi
+RUN git checkout ${WEBUI_VERSION} && git am /app/patches/*.patch
 
 WORKDIR /app