Handle 2 argument translation calls generated by Qt 5.7.1

This fixes a FTBFS error described in openscad/openscad#1872

Fix from openscad/openscad@4fa5f03

Author: hroncok

data.h

@@ -23,6 +23,12 @@ inline QString _( const char *msgid, int category )
     Q_UNUSED( category );
     return QString::fromUtf8( _( msgid ) );
 }
+inline QString _( const char *msgid, const char *disambiguation )
+{
+    Q_UNUSED(disambiguation);
+    return QString::fromUtf8(_(msgid));
+}
+
 /** END TAG */