Improved residue indexing in error messages (#4942)

* Improved residue indexing in error messages

* Fixed another one

wrappers/python/openmm/app/forcefield.py

@@ -1044,7 +1044,7 @@ class ForceField(object):
                 t1, m1 = allMatches[0]
                 for t2, m2 in allMatches[1:]:
                     if not t1.areParametersIdentical(t2, m1, m2):
-                        raise Exception('Multiple non-identical matching templates found for residue %d (%s): %s.' % (res.index+1, res.name, ', '.join(match[0].name for match in allMatches)))
+                        raise Exception('Multiple non-identical matching templates found for residue %d (%s): %s.' % (res.index, res.name, ', '.join(match[0].name for match in allMatches)))
                 template = allMatches[0][0]
                 matches = allMatches[0][1]
         return [template, matches]
@@ -1436,7 +1436,7 @@ class ForceField(object):
                     template = self._templates[tname]
                     matches = compiled.matchResidueToTemplate(res, template, data.bondedToAtom, ignoreExternalBonds, ignoreExtraParticles)
                     if matches is None:
-                        raise Exception('User-supplied template %s does not match the residue %d (%s)' % (tname, res.index+1, res.name))
+                        raise Exception('User-supplied template %s does not match the residue %d (%s)' % (tname, res.index, res.name))
                 else:
                     # Attempt to match one of the existing templates.
                     [template, matches] = self._getResidueTemplateMatches(res, data.bondedToAtom, ignoreExternalBonds=ignoreExternalBonds, ignoreExtraParticles=ignoreExtraParticles)
@@ -1471,7 +1471,7 @@ class ForceField(object):
                             # We successfully generated a residue template.  Break out of the for loop.
                             break
             if matches is None:
-                raise ValueError('No template found for residue %d (%s).  %s  For more information, see https://github.com/openmm/openmm/wiki/Frequently-Asked-Questions#template' % (res.index+1, res.name, _findMatchErrors(self, res)))
+                raise ValueError('No template found for residue %d (%s).  %s  For more information, see https://github.com/openmm/openmm/wiki/Frequently-Asked-Questions#template' % (res.index, res.name, _findMatchErrors(self, res)))
             else:
                 if recordParameters:
                     data.recordMatchedAtomParameters(res, template, matches)