Fix build failure with -Werror=format-security

See Debian bug #646258 (http://bugs.debian.org/646258) and
http://wiki.debian.org/ReleaseGoals/SecurityHardeningBuildFlags for details.
(manually cherry picked from commit d4b4060d)

dynare++/sylv/cc/SylvException.cpp

@@ -26,7 +26,7 @@ void SylvException::printMessage() const
 	char mes[1500];
 	mes[0] = '\0';
 	printMessage(mes, 1499);
-	printf(mes);
+	puts(mes);
 }
 
 int SylvException::printMessage(char* str, int maxlen) const