fix: ensure all byte output is trimmed of whitespace

This otherwise causes issues when interpreting the output as part of a variable, such as when constructing the deploying app image.

Closes #4229

plugins/apps/apps.go

@@ -1,6 +1,8 @@
 package apps
 
 import (
+	"strings"
+
 	"github.com/dokku/dokku/plugins/common"
 )
 
@@ -12,7 +14,7 @@ func ReportSingleApp(appName, infoFlag string) error {
 
 	deploySource := ""
 	if b, err := common.PlugnTriggerSetup("deploy-source", []string{appName}...).SetInput("").Output(); err != nil {
-		deploySource = string(b[:])
+		deploySource = strings.TrimSpace(string(b[:]))
 	}
 
 	locked := "false"

plugins/apps/functions.go

@@ -140,7 +140,7 @@ func maybeCreateApp(appName string) error {
 	}
 
 	b, _ := common.PlugnTriggerOutput("config-get-global", []string{"DOKKU_DISABLE_APP_AUTOCREATION"}...)
-	disableAutocreate := string(b[:])
+	disableAutocreate := strings.TrimSpace(string(b[:]))
 	if disableAutocreate == "true" {
 		common.LogWarn("App auto-creation disabled.")
 		return fmt.Errorf("Re-enable app auto-creation or create an app with 'dokku apps:create %s'", appName)