[jsfm] Upgrade jsfm to 0.21.7 in pre-build

[Hanks10100]

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[weex-bot]

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Change Log

0.21.1

• [rax] Upgrade weex-rax-framework to 0.4.1 .
• [vue] Upgrade weex-vue-framework to 2.3.3-weex.1 . (change log of Vue)
• [vue] Add weex.supports api to support feature detections. #5063
• [runtime] Fix the console API to adapt JSC on Android. WEEX-51 | #470
• [runtime] Support to pass options in callNativeModule and callNativeComponent.

0.21.2

• [Internal feature test]

0.21.3

• [Internal feature test]

0.21.4

• [rax] Upgrade weex-rax-framework to 0.4.7 .
• [rax] Add reliable type check for the last argument of taskCenter.send.

0.21.5

• [vue] Upgrade weex-vue-framework to 2.4.2-weex.3 . (change log)
• [vue] Support the <richtext> component.
• [runtime] Fix potential memory leak of callbacks in CallbackManager and TaskCenter. #550
• [runtime] Support to return values in fireEvent.

0.21.6

• [vue] Fix the $refs mismatch in vue.
• [legacy] Support to use the computed class list in legacy framework.
• [legacy] Add warnings for legacy api on Array.prototype and Object.prototype.
• [legacy] Return instance in createInstance.
• [vanilla] Remove the global id variable and the first parameter of sendTasks.

0.21.7

• [runtime] Support to send ArrayBuffer data between js and native.

[Hanks10100]

#559 is related.