Reduce size of junction zones on Coldshadow Fantasy template

This should reduce amount of huge blocked chunks of map without greatly
changing template gameplay.

Junction zones are used on one more template (Gimlis revenge), however
that template is limited to L-sized maps, so there are no massive chunks
of blocked terrain

Mods/vcmi/Content/config/rmg/hdmod/coldshadowsFantasy.json

@@ -159,7 +159,7 @@
 			},
 			"17":
 			{
-				"type" : "junction", "size" : 30,
+				"type" : "junction", "size" : 15,
 				"terrainTypeLikeZone" : 9,
 				"allowedTowns" : ["neutral"],
 				"monsters" : "strong",
@@ -172,7 +172,7 @@
 			},
 			"18":
 			{
-				"type" : "junction", "size" : 30,
+				"type" : "junction", "size" : 15,
 				"terrainTypeLikeZone" : 9,
 				"allowedTowns" : ["neutral"],
 				"monsters" : "strong",
@@ -181,7 +181,7 @@
 			},
 			"19":
 			{
-				"type" : "junction", "size" : 30,
+				"type" : "junction", "size" : 15,
 				"terrainTypeLikeZone" : 9,
 				"allowedTowns" : ["neutral"],
 				"monsters" : "strong",
@@ -190,7 +190,7 @@
 			},
 			"20":
 			{
-				"type" : "junction", "size" : 30,
+				"type" : "junction", "size" : 15,
 				"terrainTypeLikeZone" : 9,
 				"allowedTowns" : ["neutral"],
 				"monsters" : "strong",