Remove OrderedDict usage

We now support only Python 3.7+, this means we can rely on dict being
ordered by order of insertion, and thus no need to use OrderedDict from
collections.

slixmpp/plugins/xep_0004/stanza/form.py

@@ -9,7 +9,6 @@
 import copy
 import logging
 
-from collections import OrderedDict
 from slixmpp.thirdparty import OrderedSet
 
 from slixmpp.xmlstream import ElementBase, ET
@@ -133,7 +132,7 @@ class Form(ElementBase):
             self.xml.remove(reportedXML)
 
     def get_fields(self, use_dict=False):
-        fields = OrderedDict()
+        fields = {}
         for stanza in self['substanzas']:
             if isinstance(stanza, FormField):
                 fields[stanza['var']] = stanza
@@ -147,7 +146,7 @@ class Form(ElementBase):
         items = []
         itemsXML = self.xml.findall('{%s}item' % self.namespace)
         for itemXML in itemsXML:
-            item = OrderedDict()
+            item = {}
             fieldsXML = itemXML.findall('{%s}field' % FormField.namespace)
             for fieldXML in fieldsXML:
                 field = FormField(xml=fieldXML)
@@ -156,7 +155,7 @@ class Form(ElementBase):
         return items
 
     def get_reported(self):
-        fields = OrderedDict()
+        fields = {}
         xml = self.xml.findall('{%s}reported/{%s}field' % (self.namespace,
                                                            FormField.namespace))
         for field in xml:
@@ -165,7 +164,7 @@ class Form(ElementBase):
         return fields
 
     def get_values(self):
-        values = OrderedDict()
+        values = {}
         fields = self.get_fields()
         for var in fields:
             values[var] = fields[var]['value']

slixmpp/plugins/xep_0071/stanza.py

@@ -8,7 +8,6 @@
 
 from slixmpp.stanza import Message
 from slixmpp.util import unicode
-from collections import OrderedDict
 from slixmpp.xmlstream import ElementBase, ET, register_stanza_plugin, tostring
 
 
@@ -50,7 +49,7 @@ class XHTML_IM(ElementBase):
         bodies = self.xml.findall('{%s}body' % XHTML_NS)
 
         if lang == '*':
-            result = OrderedDict()
+            result = {}
             for body in bodies:
                 body_lang = body.attrib.get('{%s}lang' % self.xml_ns, '')
                 body_result = []

slixmpp/plugins/xep_0131/stanza.py

@@ -6,7 +6,6 @@
     See the file LICENSE for copying permission.
 """
 
-from collections import OrderedDict
 from slixmpp.xmlstream import ET, ElementBase
 
 
@@ -18,7 +17,7 @@ class Headers(ElementBase):
     is_extension = True
 
     def get_headers(self):
-        result = OrderedDict()
+        result = {}
         headers = self.xml.findall('{%s}header' % self.namespace)
         for header in headers:
             name = header.attrib.get('name', '')