Fix warning message typo; don't symlink onto self

symlinking onto self is a danger when doing downloads directly into the
run directory.

example/aitf-data-for-run

+#!  /home/adesmet/csppfetch/example/venv/bin/python3
 #! /usr/bin/python3
 
 # System modules
@@ -74,7 +75,7 @@ def main():
 
     cache_dir = args.dir
     if not os.access(cache_dir, os.W_OK):
-        logging.warning(f'I do not appear to be able to have write access to "{cache_dir}". Downloading directly into args.destination')
+        logging.warning(f'I do not appear to be able to have write access to "{cache_dir}". Downloading directly into {args.destination}')
         args.dir = args.destination
 
     do_download = not args.cache_only
@@ -104,7 +105,8 @@ def main():
             dst_dir = os.path.dirname(dst)
             os.makedirs(dst_dir, exist_ok=True)
             logging.info(src + ' -> ' + dst)
-            os.symlink(src, dst)
+            if src != dst:
+                os.symlink(src, dst)
 
     except csppfetch.DownloadsFailedException as e:
         logging.fatal(str(e))

example/aitf-update-cache

-#! /usr/bin/python3
+#!  /home/adesmet/csppfetch/example/venv/bin/python3
 
 # System modules
 import os