Fix logging message in shell/src/main/java/alluxio/cli/bundler/command/CollectMetricsCommand.java

[apc999]

In https://github.com/Alluxio/alluxio/blob/7aa3a6133d83931c9057b7365b99a8d0bd001bf9/shell/src/main/java/alluxio/cli/bundler/command/CollectMetricsCommand.java#L92

change LOG.error("Failed to get Alluxio metrics from URL %s. Exception is %s", url, e); to LOG.error("Failed to get Alluxio metrics from URL {}. Exception: ", url, e);

[heyingquan0030]

/assign @heyingquan13