Fix inconsistent indentation in rfc_xconf_handler.cpp

[Copilot]

Addresses feedback on PR #158 regarding mixed tabs/spaces in the hashData cleanup block.

Changes

• Replaced tabs with spaces on lines 1990 and 2001 in rfcMgr/rfc_xconf_handler.cpp
• Ensures consistent 16-space indentation matching surrounding code

// Before: tabs (inconsistent)
if(file_dwnl.hashData != nullptr)
{
    if(file_dwnl.hashData->hashvalue != nullptr)  // ← tabs here
    
    file_dwnl.hashData = nullptr;                 // ← and here
}

// After: spaces (consistent)
if(file_dwnl.hashData != nullptr)
{
    if(file_dwnl.hashData->hashvalue != nullptr)  // ← spaces now
    
    file_dwnl.hashData = nullptr;                 // ← spaces now
}

This PR merges into #158 as a stacked PR to address the specific code review feedback.

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