Remove extra dot in release tag

Author: Emad InfStones

sidechain-testnet-5/tss.md

@@ -49,7 +49,7 @@ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 ```
 git clone https://github.com/sideprotocol/shuttler.git
 cd shuttler
-git checkout v2.0.0-rc.1
+git checkout v2.0.0-rc1
 cargo build --release
 ```