Add missing type declaration.

Nowadays you're supposed to omit this type declaration, but what I didn't realize is that that feature was added in Haxe 4.1. Since Lime still needs to support earlier versions, we'll just have to do it the old way.

src/lime/system/CFFI.hx

@@ -285,7 +285,7 @@ class CFFI
 			{
 				init = load("lime", "neko_init", 5);
 			}
-			catch (e)
+			catch (e:Dynamic)
 			{
 			}