Port filter out lower levels when syncing research

Fix the next level of an infinite research getting updated with the
progress of the previous level from other nodes in the cluster by
filtering out infinite researches with a lower level than the local
level.

This is a port of 075d54f.

CHANGELOG.md

@@ -35,6 +35,8 @@ Version 1.2.2
   Object prototype property in researchSync.
 - Fixed progress of a current infinite tech carrying over to the next one
   when researching it and another node completes it in researchSync.
+- Fixed progress of a previous infinite tech from another node being applied
+  to the current one in researchSync.
 
 
 Version 1.2.1

sharedPlugins/researchSync/index.js

@@ -253,6 +253,12 @@ class ResearchSync {
 			}
             if (isNaN(cluster_techs[name].progress))
                 continue
+
+			// Do not update progress for infinite techs with a local level that's higher.
+			if (tech.infinite && tech.level > cluster_techs[name].level) {
+				continue;
+			}
+
             if (tech.progress < cluster_techs[name].progress)
                 result[name] = cluster_techs[name]
         }