simplify_regex is not cleaning up any outstanding regex-y character
    
    
    
      
      
      
        
If you try cleaning up a regex pattern involving groups, simplify_regex fails to remove a bracket.
Steps to reproduce:
run this in your shell: 
django.contrib.admindocs.views.simplify_regex('^orgs/(?P<org_id>([0-9a-f]{32}|[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}))$')
output:
'/orgs/<org_id>)'
expected output:
'/orgs/<org_id>'
       
     
   
 
      
        
        
          Change History
          (5)
        
          
  
  
  
    
      | Owner: | changed from nobody to Prajjwol Gautam | 
    
      | Status: | new → assigned | 
  
 
           
          
  
  
  
    
      | Needs tests: | set | 
    
      | Triage Stage: | Unreviewed → Accepted | 
    
      | Version: | 1.8 → master | 
  
 
           
          
          
  
  
  
    
      | Resolution: | → fixed | 
    
      | Status: | assigned → closed | 
  
 
           
          
  
  
  
    
      | Resolution: | fixed → duplicate | 
  
 
           
          
         
       
     
        
    
    
PR