fix typo

src/Solver/RubarBE.py

@@ -446,7 +446,7 @@ class Rubar3(CommandLineSolver):
                 ind = 1
                 for mail in edge.reach.inter_profiles_rk():
                     coef = get_stricklers_from_rk(mail, lst)
-                    if coeff is not None:
+                    if coef is not None:
                         f.write(f"{ind:>6} {coef:>12.5f}")
 
                     ind += 1