Fix: Persist all data different from default, not just current changes

We need to merge with our current data since we only might get partial data
from our caller.
(cherry picked from commit 7ea1578)

src/octoprint/plugin/__init__.py

@@ -446,6 +446,18 @@ class PluginSettings(object):
 		return path
 
 	def get_all_data(self, **kwargs):
+		merged = kwargs.get("merged", True)
+		asdict = kwargs.get("asdict", True)
+		defaults = kwargs.get("defaults", self.defaults)
+		preprocessors = kwargs.get("preprocessors", self.get_preprocessors)
+
+		kwargs.update(dict(
+			merged=merged,
+			asdict=asdict,
+			defaults=defaults,
+			preprocessors=preprocessors
+		))
+
 		return self.settings.get(self._prefix_path(), **kwargs)
 
 	def clean_all_data(self):

src/octoprint/plugin/types.py

@@ -813,12 +813,17 @@ class SettingsPlugin(OctoPrintPlugin):
 		"""
 		import octoprint.util
 
-		if self.config_version_key in data:
-			del data[self.config_version_key]
+		# get the current data
+		current = self._settings.get_all_data()
+
+		# merge our new data on top of it
+		new_current = octoprint.util.dict_merge(current, data)
+		if self.config_version_key in new_current:
+			del new_current[self.config_version_key]
 
 		# determine diff dict that contains minimal set of changes against the
 		# default settings - we only want to persist that, not everything
-		diff = octoprint.util.dict_diff(self.get_settings_defaults(), data)
+		diff = octoprint.util.dict_diff(self.get_settings_defaults(), new_current)
 
 		version = self.get_settings_version()