Drop emit on mounted

I don't think this makes sense, value is a prop, so on mount there's no
change and so `this.parameter.field.value(this.value)` will not have
been called.

client/src/components/Form/Elements/FormParameter.vue

@@ -53,7 +53,6 @@ export default {
                     }
                 },
             });
-            this.$emit("input", this.parameter.field.value());
         });
     },
     beforeDestroy() {