Description of problem:
The "Author search" feature is broken.

Version-Release number of selected component (if applicable):


How reproducible:
Always.

Steps to Reproduce:
1. Start slrn, enter a group
2. Press 'a' to search by author
3. Enter a search term that obviously should be found
  
Actual results:
The search doesn't find anything (or at least not what you wanted). That is
because it is searching for _subjects_, not authors.

Expected results:
Should be searching for authors with author search.

Additional info:
This bug exists in all FC versions from (at least) FC5 to FC7test1. I found a
fix from slrn's CVS, please see the attached patch. A simple 2-line fix.