Remove / Update supported bee version

[rampall]

gateway-proxy/README.md

Line 18 in 55b6936

**Bee&nbsp;version&nbsp;<!-- SUPPORTED_BEE_START -->1.7.0-bbf13011<!-- SUPPORTED_BEE_END -->**. Using it with older or

[aranyia]

+1 Would be good to remove this, and to update the relevant parts of the README as well. If I am not mistaken, the latest release (PR #497) was about to keep compatibility with the latest Bee 2.x node versions.