Fix exception when loading adjacency with empty source or target (#1859…

…) #patch

Sentry event ID: 08db0b07237b4437a57493f62363e30e

ImperatorToCK3/CommonUtils/Map/MapData.cs

@@ -448,8 +448,12 @@ private void LoadAdjacencies(string adjacenciesFilename, ModFilesystem modFS) {
 				if (toStr == "-1") {
 					continue;
 				}
-
-				AddAdjacency(ulong.Parse(fromStr, CultureInfo.InvariantCulture), ulong.Parse(toStr, CultureInfo.InvariantCulture));
+
+				if (!ulong.TryParse(fromStr, out var from) || !ulong.TryParse(toStr, out var to)) {
+					continue;
+				}
+
+				AddAdjacency(from, to);
 				++count;
 			}
 		}