[SCB-503]Fix stateful access problem and resource leak issue related to WeighedResponseTimeRule

[liubao68]

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[wujimin]

paste compile warning check image please.

[coveralls]

Coverage decreased (-0.07%) to 87.371% when pulling 33769e9 on liubao68:config into 41049be on apache:master.

[liubao68]

I am using eclipse and all compile warnings fixed except #652