Fix #1685: Harmony parsing errors with doubled characters (#1688)

The code intended to only remove the parsed `chordKind` from the string, but in cases where the `chordKind` char occurs multiple times, this would remove all occurrences of the char.

music21/harmony.py

@@ -1890,7 +1890,7 @@ def _getKindFromShortHand(self, sH):
             for charString in getAbbreviationListGivenChordType(chordKind):
                 if sH == charString:
                     self.chordKind = chordKind
-                    return originalsH.replace(charString, '')
+                    return originalsH[len(sH):]
         return originalsH
 
     def _hasPitchAboveC4(self, pitches):
@@ -3162,6 +3162,12 @@ def testExpressSusUsingAlterations(self):
 
         self.assertEqual(ch1.pitches, ch2.pitches)
 
+    def testDoubledCharacters(self):
+        ch1 = ChordSymbol('Co omit5')
+        ch2 = ChordSymbol('Cdim omit5')
+
+        self.assertEqual(ch1.pitches, ch2.pitches)
+
     def x_testPower(self):
         '''
         power chords should not have inversions