Fix UT

On my box this test was failing because mock server hostname was
127.0.0.1 and not localhost

Author: henryju

api/src/test/java/org/sonarsource/scanner/api/internal/ServerConnectionTest.java

@@ -108,7 +108,7 @@ public void should_throw_ISE_if_response_not_successful() throws Exception {
     ServerConnection underTest = create(false, false);
     assertThatThrownBy(() -> underTest.downloadFile("/batch/index.txt", toFile))
       .isInstanceOf(IllegalStateException.class)
-      .hasMessage(format("Status returned by url [http://localhost:%d/batch/index.txt] is not valid: [400]", server.getPort()));
+      .hasMessage(format("Status returned by url [http://%s:%d/batch/index.txt] is not valid: [400]", server.getHostName(), server.getPort()));
   }
 
   @Test