fix bug with %'S and %"S

Signed-off-by: Jade Abraham <[email protected]>

syntaxes/chapel.tmLanguage.json

@@ -171,7 +171,7 @@
           "name": "constant.other.placeholder.chapel"
         },
         {
-          "match": "(%(@|\\+|0|<|>|\\^)*(\\*|[0-9]+)?(\\.[0-9]*)?[dxXobjh'\"]?[eE]?([niurmzsSc]|([{](.S|\\*S|.S.)[}])|(/.*/)|([{]/.*/[a-zA-Z]+[}]))?)",
+          "match": "(%(@|\\+|0|<|>|\\^)*(\\*|[0-9]+)?(\\.[0-9]*)?(?:[dxXobjh]|(?:[\\\\]?['\"][S]))?[eE]?([niurmzsSc]|([{](.S|\\*S|.S.)[}])|(/.*/)|([{]/.*/[a-zA-Z]+[}]))?)",
           "name": "constant.other.placeholder.chapel"
         },
         {