Remove hardcoded URL that breaks API connectivity

[davidastephens]

Problem

Commit 0a4989c introduced a hardcoded URL override in request_statement() that breaks API connectivity:

def request_statement(token: str, query_id: str, url: Optional[str] = None) -> StatementAccess:
    """First part of the 2-step download process."""
    url = url or REQUEST_URL
    ### AKE FIX
    url = 'https://ndcdyn.interactivebrokers.com/portal.flexweb/api/v1/flexQuery'  # ← BREAKS CONNECTIVITY
    response = submit_request(url, token, query=query_id)
    ...

This hardcoded URL causes timeout errors for users:

Request Timeout, re-sending...

Impact

• Users cannot connect to IB FlexQuery API
• The url parameter is completely ignored
• Applications using this library are broken
• Affects all users who upgraded to commit 0a4989c or later

Root Cause

The hardcoded URL https://ndcdyn.interactivebrokers.com/portal.flexweb/api/v1/flexQuery appears to be a non-standard endpoint that doesn't work for most users. The standard endpoint is:

REQUEST_URL = 'https://gdcdyn.interactivebrokers.com/Universal/servlet/FlexStatementService.SendRequest'

Solution

Remove the 2-line hardcoded URL override and restore the original logic:

url = url or REQUEST_URL

This allows:

• Default behavior: use REQUEST_URL
• Custom URLs: pass via url parameter
• Proper API connectivity for all users

Testing

• ✅ Tested with production IB accounts
• ✅ API connections work after removing hardcoded URL
• ✅ API connections fail with the hardcoded URL

Changes

• Remove 2 lines that hardcode the URL
• Restore original URL selection logic
• No other changes needed

This is a critical fix for API connectivity.