Stop setting default node name to graylog-sidecar (#346)

Removed the lines to default the node name to graylog-sidecar. 
The current action doesn't match the documentation.
# The node name of the sidecar. If this is empty, the sidecar will use the
# hostname of the host it is running on.

(cherry picked from commit b7c0048)

dist/recipe.nsi

@@ -208,9 +208,6 @@ Section "Post"
   ${If} $ServerUrl == ""
     StrCpy $ServerUrl "http://127.0.0.1:9000/api"
   ${EndIf}
-  ${If} $NodeName == ""
-    StrCpy $NodeName "graylog-sidecar"
-  ${EndIf}
   ${If} $UpdateInterval == ""
     StrCpy $UpdateInterval "10"
   ${EndIf}