we should change thrift version in master branch

[HarrisChu]

currently, the version in common.thrift is still 2.6.0, and we update the client, e.g. nebula-go, nebula-console.
It will make user confused if he download the latest nebula-import to connect nebula v2.6.0.
https://discuss.nebula-graph.com.cn/t/topic/7006/9

we should update the version, and then when using the latest client, it would raise an incompatible error.

[HarrisChu]

as talked offline, won't change the version util release.

[wey-gu]

Could we always mark version info in master as something different from the last tag/release to remove the confusion, this applies to all repo including studio, clients, other utils.