Fix: nodewrangler error accessing space.node_tree when not available

Revert part of rBAad1966474ed2 in nw_check() which was giving no benefit
afaict (and instead tried to access space.node_tree for Spaces other
than the Node Editor, spamming the console with errors).

Differential Revision: https://developer.blender.org/D15770

node_wrangler.py

@@ -830,12 +830,13 @@ class NWNodeWrangler(bpy.types.AddonPreferences):
 
 def nw_check(context):
     space = context.space_data
-    editor_is_valid = space.type == 'NODE_EDITOR'
-
     valid_trees = ["ShaderNodeTree", "CompositorNodeTree", "TextureNodeTree", "GeometryNodeTree"]
-    tree_is_valid = space.node_tree is not None and space.tree_type in valid_trees
 
-    return editor_is_valid and tree_is_valid
+    valid = False
+    if space.type == 'NODE_EDITOR' and space.node_tree is not None and space.tree_type in valid_trees:
+        valid = True
+
+    return valid
 
 class NWBase:
     @classmethod