Fix the Dockerfile sed command (Closes #2938)

Author: TheFrenchGhosty

docker/Dockerfile

@@ -42,7 +42,7 @@ RUN addgroup -g 1000 -S invidious && \
     adduser -u 1000 -S invidious -G invidious
 COPY --chown=invidious ./config/config.* ./config/
 RUN mv -n config/config.example.yml config/config.yml
-RUN sed -i 's/host: \(127.0.0.1\|localhost\)/host: postgres/' config/config.yml
+RUN sed -i 's/host: \(127.0.0.1\|localhost\)/host: invidious-db/' config/config.yml
 COPY ./config/sql/ ./config/sql/
 COPY ./locales/ ./locales/
 COPY --from=builder /invidious/assets ./assets/

docker/Dockerfile.arm64

@@ -41,7 +41,7 @@ RUN addgroup -g 1000 -S invidious && \
     adduser -u 1000 -S invidious -G invidious
 COPY --chown=invidious ./config/config.* ./config/
 RUN mv -n config/config.example.yml config/config.yml
-RUN sed -i 's/host: \(127.0.0.1\|localhost\)/host: postgres/' config/config.yml
+RUN sed -i 's/host: \(127.0.0.1\|localhost\)/host: invidious-db/' config/config.yml
 COPY ./config/sql/ ./config/sql/
 COPY ./locales/ ./locales/
 COPY --from=builder /invidious/assets ./assets/