fix bug with ignored CAS

Author: yoelcortes

thermosteam/_chemical.py

@@ -553,7 +553,7 @@ def __new__(cls, ID, cache=None, *, search_ID=None,
             except LookupError as error:
                 # Try BioSTEAM
                 self = search_biorefinery_chemicals(search_ID, error)
-                if CAS is not None: self._CAS = CAS
+            if CAS is not None: self._CAS = CAS
         elif db in ('biosteam', 'thermosteam'):
             self = search_biorefinery_chemicals(search_ID)
             if CAS is not None: self._CAS = CAS