Merge pull request 20tab#631 from dfb/pr_python_home_env

look for python in alternate custom location

Author: rdeioris

Source/UnrealEnginePython/UnrealEnginePython.Build.cs

@@ -292,6 +292,11 @@ private string DiscoverPythonPath(string[] knownPaths, string binaryPath)
         if (!string.IsNullOrEmpty(environmentPath))
             paths.Insert(0, environmentPath);
 
+        // look in an alternate custom location
+        environmentPath = System.Environment.GetEnvironmentVariable("UNREALENGINEPYTHONHOME");
+        if (!string.IsNullOrEmpty(environmentPath))
+            paths.Insert(0, environmentPath);
+
         foreach (string path in paths)
         {
             string actualPath = path;