fixup! ABI coder v1

Author: matheusaaguiar

libsolidity/analysis/SyntaxChecker.cpp

@@ -151,8 +151,8 @@ bool SyntaxChecker::visit(PragmaDirective const& _pragma)
 			m_sourceUnit->annotation().useABICoderV2 = (_pragma.literals()[1] == "v2");
 
 		if (
-			m_sourceUnit->annotation().useABICoderV2.set() &&
-			!*m_sourceUnit->annotation().useABICoderV2
+			_pragma.literals().size() > 1 &&
+			_pragma.literals()[1] == "v1"
 		)
 			m_errorReporter.warning(
 				9511_error,