[FAB-8273] Fix Jira link in root README.md

Points the first Jira link in the root README.md to the main
Fabric dashboard in Jira.

Change-Id: I25a9bd13224860c77e81a58c57e294bd1c2c1c61
Signed-off-by: Sheehan Anderson <sranderson@gmail.com>

Author: srderson

README.md

@@ -1,6 +1,6 @@
 
 **Note:** This is a **read-only mirror** of the formal [Gerrit](https://gerrit.hyperledger.org/r/#/admin/projects/fabric) repository,
-where active development is ongoing. Issue tracking is handled in [Jira](https://jira.hyperledger.org/secure/RapidBoard.jspa?projectKey=FAB&rapidView=5&view=planning)
+where active development is ongoing. Issue tracking is handled in [Jira](https://jira.hyperledger.org/secure/Dashboard.jspa?selectPageId=10104)
 
 ## Status