gnu: guile-opengl: Build with Guile 2.2.

* gnu/packages/gl.scm (guile-opengl): Build with Guile 2.2.

gnu/packages/gl.scm

@@ -420,7 +420,7 @@ (define-public guile-opengl
                "13qfx4xh8baryxqrv986l848ygd0piqwm6s2s90pxk9c0m9vklim"))))
     (build-system gnu-build-system)
     (native-inputs `(("pkg-config" ,pkg-config)))
-    (inputs `(("guile" ,guile-2.0)
+    (inputs `(("guile" ,guile-2.2)
               ("mesa" ,mesa)
               ("glu" ,glu)
               ("freeglut" ,freeglut)))