Bug 542101: [GTK3] Increase minimum GTK3 version to 3.8.0

Bump minimum version to 3.8.0 to avoid JVM symbol lookup errors for an
a11y macro which was not public before 3.8.0.

Change-Id: Ia9cbca30070907ab9904fdf75c195fa76ff29488
Signed-off-by: Eric Williams <ericwill@redhat.com>
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
index ffb9c51..3c6a1c5 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
@@ -468,7 +468,7 @@
 
 	/* GTK Version */
 	static final int GTK3_MAJOR = 3;
-	static final int GTK3_MINOR = 6;
+	static final int GTK3_MINOR = 8;
 	static final int GTK3_MICRO = 0;
 
 	/* Display Data */