Increase speed of flowing water/river water animations

To visually match the 1 node per second spread of flowing water.

mods/default/nodes.lua

@@ -2234,7 +2234,7 @@ minetest.register_node("default:water_flowing", {
 				type = "vertical_frames",
 				aspect_w = 16,
 				aspect_h = 16,
-				length = 0.8,
+				length = 0.5,
 			},
 		},
 		{
@@ -2244,7 +2244,7 @@ minetest.register_node("default:water_flowing", {
 				type = "vertical_frames",
 				aspect_w = 16,
 				aspect_h = 16,
-				length = 0.8,
+				length = 0.5,
 			},
 		},
 	},
@@ -2330,7 +2330,7 @@ minetest.register_node("default:river_water_flowing", {
 				type = "vertical_frames",
 				aspect_w = 16,
 				aspect_h = 16,
-				length = 0.8,
+				length = 0.5,
 			},
 		},
 		{
@@ -2340,7 +2340,7 @@ minetest.register_node("default:river_water_flowing", {
 				type = "vertical_frames",
 				aspect_w = 16,
 				aspect_h = 16,
-				length = 0.8,
+				length = 0.5,
 			},
 		},
 	},