Fixed syntax warnings

Author: tijmenNL

sipsimple/account/bonjour/_bonjour.py

@@ -1892,7 +1892,7 @@ def DNSServiceConstructFullName(
     domain = _NO_DEFAULT,
     ):
 
-    """
+    r"""
 
     Concatenate a three-part domain name (as returned by a callback
     function) into a properly-escaped full domain name.  Note that

sipsimple/lookup-gevent.py

@@ -175,7 +175,7 @@ def lookup_service(self, uri, service, timeout=3.0, lifetime=15.0):
 
         try:
             # If the host part of the URI is an IP address, we will not do any lookup
-            if re.match("^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
+            if re.match(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
                 return [(uri.host.decode(), uri.port or service_port)]
 
             resolver = DNSResolver()
@@ -232,7 +232,7 @@ def lookup_sip_proxy(self, uri, supported_transports, timeout=3.0, lifetime=15.0
         try:
             # If the host part of the URI is an IP address, we will not do any lookup
             transport = uri.transport.decode() if isinstance(uri.transport, bytes) else uri.transport
-            if re.match("^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
+            if re.match(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
                 transport = 'tls' if uri.secure else transport.lower()
                 if transport not in supported_transports:
                     raise DNSLookupError("IP transport %s dictated by URI is not supported" % transport)
@@ -325,7 +325,7 @@ def lookup_xcap_server(self, uri, timeout=3.0, lifetime=15.0):
 
         try:
             # If the host part of the URI is an IP address, we cannot not do any lookup
-            if re.match("^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
+            if re.match(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", uri.host.decode()):
                 raise DNSLookupError("Cannot perform DNS query because the host is an IP address")
 
             resolver = DNSResolver()