fix changelog PR number (git commit -am 'hooray! got a different error this time. Now just guesswork though....'! I didn't check the AI autocomplete... how did it come up with 3300?)

Author: keflavich

CHANGES.rst

@@ -22,7 +22,7 @@ alma
 linelists.cdms
 ^^^^^^^^^^^^^^
 
-- Add a keyword to control writing of new species cache files.  This is needed to prevent tests from overwriting those files. [#3300]
+- Add a keyword to control writing of new species cache files.  This is needed to prevent tests from overwriting those files. [#3297]
 
 heasarc
 ^^^^^^^