fix: multipart enum initial value

Signed-off-by: mathis-m <mathis.michel@outlook.de>

src/core/plugins/oas3/components/request-body.jsx

@@ -155,7 +155,7 @@ const RequestBody = ({
               const currentValue = requestBodyValue.getIn([key, "value"])
               const currentErrors = requestBodyValue.getIn([key, "errors"]) || requestBodyErrors
               const included = requestBodyInclusionSetting.get(key) || false
-              let hasNonEmptyInitialVal = prop.has("default") || prop.has("example") || prop.hasIn(["items", "example"]) || prop.hasIn(["items", "default"]) || prop.has("enum") && prop.get("enum").size === 1
+              let hasNonEmptyInitialVal = prop.has("default") || prop.has("example") || prop.hasIn(["items", "example"]) || prop.hasIn(["items", "default"]) || prop.has("enum") && prop.get("enum").size > 0
               let initialValue = ""
               if(type === "array" && !hasNonEmptyInitialVal) {
                 initialValue = []