Fix bugs in the configs of Libra R-CNN (#738)

* Fix bugs in the configs of Libra R-CNN

* return configs to 2000 props

* return configs to 1000 props

configs/libra_rcnn/libra_fast_rcnn_r50_fpn_1x.py

@@ -62,8 +62,8 @@ train_cfg = dict(
             pos_sampler=dict(type='InstanceBalancedPosSampler'),
             neg_sampler=dict(
                 type='IoUBalancedNegSampler',
-                floor=-1,
-                floor_thr=0,
+                floor_thr=-1,
+                floor_fraction=0,
                 num_bins=3)),
         pos_weight=-1,
         debug=False))

configs/libra_rcnn/libra_faster_rcnn_r101_fpn_1x.py

@@ -97,8 +97,8 @@ train_cfg = dict(
             pos_sampler=dict(type='InstanceBalancedPosSampler'),
             neg_sampler=dict(
                 type='IoUBalancedNegSampler',
-                floor=-1,
-                floor_thr=0,
+                floor_thr=-1,
+                floor_fraction=0,
                 num_bins=3)),
         pos_weight=-1,
         debug=False))

configs/libra_rcnn/libra_faster_rcnn_r50_fpn_1x.py

@@ -97,8 +97,8 @@ train_cfg = dict(
             pos_sampler=dict(type='InstanceBalancedPosSampler'),
             neg_sampler=dict(
                 type='IoUBalancedNegSampler',
-                floor=-1,
-                floor_thr=0,
+                floor_thr=-1,
+                floor_fraction=0,
                 num_bins=3)),
         pos_weight=-1,
         debug=False))

configs/libra_rcnn/libra_faster_rcnn_x101_64x4d_fpn_1x.py

@@ -99,8 +99,8 @@ train_cfg = dict(
             pos_sampler=dict(type='InstanceBalancedPosSampler'),
             neg_sampler=dict(
                 type='IoUBalancedNegSampler',
-                floor=-1,
-                floor_thr=0,
+                floor_thr=-1,
+                floor_fraction=0,
                 num_bins=3)),
         pos_weight=-1,
         debug=False))