graphics/qgis: Missing build dependency

[rhurlin]

Summary

pkg-fallout@ complains about failing for qgis-3.16.0 in package[1]. It turns out, that I committed a pre-version of Makefile, which missed BUILD_DEPENDS=devel/opencl. Sorry for any inconvenience.

[1] http://beefy18.nyi.freebsd.org/data/head-amd64-default/p553574_s367123/logs/qgis-3.16.0.log

head/graphics/qgis/Makefile

+#ifndef VERIFY_H
+#define VERIFY_H
+
+int verify(const char*);
+
+#endif  /* VERIFY_H */