update version to v0.8.2 in manual instructions

Author: openoms

build_joininbox.md

@@ -118,7 +118,7 @@ https://docs.armbian.com/User-Guide_Getting-Started/#how-to-check-download-authe
     git clone https://github.com/JoinMarket-Org/joinmarket-clientserver.git
     cd joinmarket-clientserver
     # latest release: https://github.com/JoinMarket-Orgjoinmarket-clientserver/releases
-    git reset --hard v0.6.3.1
+    git reset --hard v0.8.2
     ./install.sh --without-qt
     ```
 ### Set up JoinMarket