Explicitly use BlackLab api v4 for now

Author: KCMertens

src/frontend/src/api/index.ts

@@ -48,7 +48,10 @@ export function init(which: keyof typeof endpoints, url: string, user: User|null
 	endpoints[which] = createEndpoint({
 		baseURL: url.replace(/\/*$/, '/'),
 		paramsSerializer: params => qs.stringify(params),
-		headers
+		headers,
+		params: which === 'blacklab' ? {
+			api: '4' // backward compat
+		} : undefined,
 	});
 }
 

src/main/java/nl/inl/corpuswebsite/utils/BlackLabApi.java

@@ -27,7 +27,8 @@ public BlackLabApi(HttpServletRequest clientRequest, HttpServletResponse clientR
 	}
 
 	private AuthRequest authRequest() {
-		var req = new AuthRequest(request, response);
+		var req = new AuthRequest(request, response)
+			.query("api", "4"); // compat
 
 		readRequestParameter(request, config.get(Keys.AUTH_SOURCE_TYPE), config.get(Keys.AUTH_SOURCE_NAME))
 				.ifPresent(auth -> setParameter(req, config.get(Keys.AUTH_TARGET_TYPE), config.get(Keys.AUTH_TARGET_NAME), auth));