Fix python3 binary - character mismatch in api.py

Convert between text and binary data in api.py call to urllib.request
and response from it.

In python3 sqlmapapi -c it fixes, at least
- not nice output from log/list commands
- any command that POSTs data (including new) crashing sqlmapapi

lib/utils/api.py

@@ -713,7 +713,7 @@ def _client(url, options=None):
     try:
         data = None
         if options is not None:
-            data = jsonize(options)
+            data = jsonize(options).encode("utf-8")
         headers = {"Content-Type": "application/json"}
 
         if DataStore.username or DataStore.password:
@@ -721,7 +721,7 @@ def _client(url, options=None):
 
         req = _urllib.request.Request(url, data, headers)
         response = _urllib.request.urlopen(req)
-        text = response.read()
+        text = response.read().decode("utf-8")
     except:
         if options:
             logger.error("Failed to load and parse %s" % url)