update deprecated postprocess type

app.py

@@ -178,7 +178,7 @@ with col3:
         "overlap_ratio", min_value=0.0, max_value=0.6, value=0.2, step=0.2
     )
     postprocess_type = st.selectbox(
-        "postprocess_type", options=["NMS", "UNIONMERGE"], index=1
+        "postprocess_type", options=["NMS", "GREEDYNMM"], index=1
     )
     postprocess_match_metric = st.selectbox(
         "postprocess_match_metric", options=["IOU", "IOS"], index=1