Remove 0 bandwidth condition on drop frames

Do not rely on special encoder configured target bit-rate to
conduct drop frame decision.

BUG=b/259125515

Change-Id: I13529f12ce8be930cf2751c95374d45c4bd8bcea
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 05bbed1..b48aa2f 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -3648,7 +3648,7 @@
   // Never drop on key frame.
   if (has_no_stats_stage(cpi) && oxcf->rc_cfg.mode == AOM_CBR &&
       current_frame->frame_type != KEY_FRAME) {
-    if (cpi->oxcf.rc_cfg.target_bandwidth == 0 || av1_rc_drop_frame(cpi)) {
+    if (av1_rc_drop_frame(cpi)) {
       av1_setup_frame_size(cpi);
       av1_set_mv_search_params(cpi);
       av1_rc_postencode_update_drop_frame(cpi);