Add a hyphen doc string for error

Signed-off-by: mulhern <amulhern@redhat.com>

Author: mulkieran

src/stratis_cli/_errors.py

@@ -458,7 +458,7 @@ def __str__(self):
 
 class StratisCliInPlaceNotSpecified(StratisCliUserError):
     """
-    Raised if the user requested in place encryption but did not use the
+    Raised if the user requested in-place encryption but did not use the
     --in-place option.
     """