Update properties.json

Author: lzehl

vocab/properties.json

@@ -148,7 +148,7 @@
       }
     ],
     "label": "MT pulse shape",
-    "labelPlural": "MT pulse shape",
+    "labelPlural": "MT pulse shapes",
     "name": "MTPulseShape",
     "namePlural": "MTPulseShapes",
     "usedIn": {