Fix typos detected by github.com/client9/misspell

(cherry picked from commit be211ceead)

spring-test/src/main/java/org/springframework/test/web/reactive/server/WebTestClient.java

@@ -197,7 +197,7 @@ public interface WebTestClient {
 	 * without an HTTP server using a mock request and response.
 	 * <p>Consider using the TestContext framework and
 	 * {@link org.springframework.test.context.ContextConfiguration @ContextConfiguration}
-	 * in order to efficently load and inject the Spring configuration into the
+	 * in order to efficiently load and inject the Spring configuration into the
 	 * test class.
 	 * @param applicationContext the Spring context
 	 * @return chained API to customize server and client config; use