internal/cveschema: accept a single string for credit field

Change-Id: I3bf79b8450728af743051e2f4b2191665e1a6375
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/382374
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Julie Qiu <julie@golang.org>
diff --git a/internal/cveschema/cveschema.go b/internal/cveschema/cveschema.go
index 6ad3a54..d119898 100644
--- a/internal/cveschema/cveschema.go
+++ b/internal/cveschema/cveschema.go
@@ -289,5 +289,16 @@
 		return Credit{Data: CreditData{Description: Description{Data: ls}}}, nil
 	}
 
+	var str string
+	if err := json.Unmarshal(raw, &str); err == nil {
+		return Credit{
+			Data: CreditData{
+				Description: Description{
+					Data: []LangString{{Lang: "eng", Value: str}},
+				},
+			},
+		}, nil
+	}
+
 	return Credit{}, errors.New("could not parse credit field")
 }