The "error" property should be a string not a boolean

The "error" property of the Login class object carries information about which type of login error
has been thrown, which is later used to build the message key to retrieve the corresponding
translated message to show to users.

Therefore it should remain a string, and not simply a boolean.

src/cita/wikidata.ts

@@ -1065,12 +1065,12 @@ export default class {
 class Login {
 	cancelled: any;
 	anonymous: any;
-	error: boolean;
+	error: string;
 	username: any;
 	password: any;
 	save?: boolean;
 	constructor() {
-		this.error = false;
+		this.error = "";
 	}
 
 	get credentials() {
@@ -1082,23 +1082,23 @@ class Login {
 	}
 
 	onError(error: Error) {
-		this.error = false;
+		this.error = "";
 		if (error.name == "badtoken") {
 			if (this.anonymous) {
 				// See https://github.com/maxlath/wikibase-edit/issues/63
 				// fix: not sure if this should be bool or string?
-				this.error = true; //'unsupportedAnonymous';
+				this.error = 'unsupportedAnonymous';
 			} else {
 				debug("Unexpected login error", error);
-				this.error = true; // = 'unknown';
+				this.error = 'unknown';
 			}
 		} else if (error.message.split(":")[0] == "failed to login") {
 			const reason = error.message.split(":")[1].trim();
 			if (reason === "invalid username/password") {
-				this.error = true; // = 'wrongCredentials';
+				this.error = 'wrongCredentials';
 			} else {
 				debug("Unexpected login error", error);
-				this.error = true; // = 'unknown';
+				this.error = 'unknown';
 			}
 		}
 		// I don't want permissiondenied errors to be treated as
@@ -1111,7 +1111,7 @@ class Login {
 	}
 
 	onSuccess() {
-		this.error = false;
+		this.error = "";
 		if (!this.anonymous && this.save) {
 			debug("Saving credentials to be implemented");
 		}