MNT: drop unused variables reported by pyflakes

Author: pavoljuhas

Diff for: src/diffpy/srfit/fitbase/constraint.py

@@ -109,7 +109,7 @@ def _validate(self):
         try:
             val = self.eq()
             self.par.setValue(val)
-        except TypeError as e:
+        except TypeError:
             raise SrFitError("eq cannot be evaluated")
         finally:
             if val is None:

Diff for: src/diffpy/srfit/fitbase/fitcontribution.py

@@ -355,7 +355,7 @@ def _validate(self):
             raise SrFitError(e)
         try:
             val = self.residual()
-        except TypeError as e:
+        except TypeError:
             raise SrFitError("residual cannot be evaluated")
         if val is None:
             raise SrFitError("residual evaluates to None")

Diff for: src/diffpy/srfit/fitbase/restraint.py

@@ -107,7 +107,7 @@ def _validate(self):
         # Try to get the value of eq.
         try:
             val = self.eq()
-        except TypeError as e:
+        except TypeError:
             raise SrFitError("eq cannot be evaluated")
         finally:
             if val is None: