Update solvent_reboiler.py (#734)

Co-authored-by: Ludovico Bianchi <[email protected]>
(cherry picked from commit 9964c6f)

Author: jalving

Diff for: idaes/generic_models/unit_models/column_models/solvent_reboiler.py

@@ -267,7 +267,7 @@ def build(self):
         flow_basis = self.vapor_phase[t_init].get_material_flow_basis()
         if flow_basis == MaterialFlowBasis.molar:
             fb = "flow_mole"
-        elif flow_basis == MaterialFlowBasis.molar:
+        elif flow_basis == MaterialFlowBasis.mass:
             fb = "flow_mass"
         else:
             raise ConfigurationError(