Allow overwrite of tap metadata

It seems to be possible for a datalinker container to get in a state where it is trying to start up, but fails because it is trying to download TAP metadata for a second time and unzip interactively prompts to overwrite.  Add the allow-overwrite flag so it can get past this state.

scripts/start-frontend.sh

@@ -6,7 +6,7 @@ if [ -n "$DATALINKER_TAP_METADATA_URL" ]; then
         exit 1
     fi
     curl -L "$DATALINKER_TAP_METADATA_URL" -o /tmp/datalink-columns.zip
-    unzip /tmp/datalink-columns.zip -d "$DATALINKER_TAP_METADATA_DIR"
+    unzip -o /tmp/datalink-columns.zip -d "$DATALINKER_TAP_METADATA_DIR"
 fi
 
 rm -rf /tmp/secrets