🎨 Fix '…if_chain' Uncrustify option

buildroot/share/extras/uncrustify.cfg

 mod_full_brace_do                 = false
 mod_full_brace_for                = false
 mod_full_brace_if                 = false
-mod_full_brace_if_chain           = true
+mod_full_brace_if_chain           = 1
 mod_full_brace_while              = false
 mod_remove_extra_semicolon        = true
 newlines                          = lf