fix: if creator_seq is an overly long string, don't print

This fix was added due to @msdemlei comment in #492

pyvo/registry/regtap.py

@@ -837,7 +837,9 @@ def describe(self, verbose=False, width=78, file=None):
         if verbose:
             if self.source_value:
                 print(f"\nSource: {self.source_value}", file=file)
-            if self.creators:
+            # don't print creators if it's an overly long string 
+            # not separated by semicolons
+            if self.creators and len(self.creators[0]) < width:
                 nmax_authors = 5
                 if len(self.creators) <= nmax_authors:
                     print(f"Authors: {', '.join(self.creators)}", file=file)