Update java version in NFR (#439)

docs/DeveloperGuide.md

@@ -617,7 +617,7 @@ Priorities: High (must have) - `* * *`, Medium (nice to have) - `* *`, Low (unli
 
 ### Non-Functional Requirements
 
-1. Should work on any _mainstream OS_ as long as it has Java `17` or above installed.
+1. Should work on any _mainstream OS_ as long as it has Java `17` installed.
 2. A user with above average typing speed for regular English text (i.e. not code, not system admin commands) should be able to accomplish most of the tasks faster using commands than using the mouse.
 3. Should be for a single user i.e. (not a multi-user product) and should not involve data sharing across users.
 4. The data should be stored locally and should be in a human-readable format.