Update fragment_utils.py

Author: donerancl

rmgpy/molecule/fragment_utils.py

@@ -361,8 +361,6 @@ def check_if_pibond_near_cutting_label(species_smiles):
 def merge_fragment_a_to_cutting_label_on_b(smiles_a,smiles_b,cuttinglabel):
     a_frag = Fragment().from_smiles_like_string(smiles_a)
     b_frag = Fragment().from_smiles_like_string(smiles_b)
-    if "RL".replace(cuttinglabel.symbol,"") not in [x.symbol for x in a_frag.atoms]:
-        return "ERROR"
     for vertex in b_frag.vertices:
         if isinstance(vertex, CuttingLabel):