Fix python not being resolved correctly if not in path (#4864)

* Don't replace plugin exec path if python command. Don't clobber exec
* Fix logging of python resolve errors

pkg/plugin/config.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/stashapp/stash/pkg/plugin/hook"
+	"github.com/stashapp/stash/pkg/python"
 	"github.com/stashapp/stash/pkg/utils"
 	"gopkg.in/yaml.v2"
 )
@@ -294,16 +295,18 @@ func (c Config) getConfigPath() string {
 }
 
 func (c Config) getExecCommand(task *OperationConfig) []string {
-	ret := c.Exec
+	// #4859 - don't modify the original exec command
+	ret := append([]string{}, c.Exec...)
 
 	if task != nil {
 		ret = append(ret, task.ExecArgs...)
 	}
 
-	if len(ret) > 0 {
+	// #4859 - don't use the plugin path in the exec command if it is a python command
+	if len(ret) > 0 && !python.IsPythonCommand(ret[0]) {
 		_, err := exec.LookPath(ret[0])
 		if err != nil {
-			// change command to use absolute path
+			// change command to run from the plugin path
 			pluginPath := filepath.Dir(c.path)
 			ret[0] = filepath.Join(pluginPath, ret[0])
 		}