Update RomeoFoxtrot_mod.yara.error

The $challenge is not defined. Recommend to remove it so that this rule could be imported.

malware/Operation_Blockbuster/RomeoFoxtrot_mod.yara.error

@@ -52,6 +52,6 @@ rule RomeoFoxtrot
 		$response = "RESPONSE 200 OK!!!"
 
 	condition:
-		($challenge and $response) or 
+		$response or 
 		$connect in ((pe.sections[pe.section_index(".text")].raw_data_offset)..(pe.sections[pe.section_index(".text")].raw_data_offset + pe.sections[pe.section_index(".text")].raw_data_size))
 }