strip out \r on export

(private post)
https://anki.tenderapp.com/discussions/ankidesktop/42315-bug-report-exporting-selected-cards-in-browser-issue

pylib/anki/exporting.py

@@ -52,6 +52,7 @@ class Exporter:
         # fixme: we should probably quote fields with newlines
         # instead of converting them to spaces
         text = text.replace("\n", " ")
+        text = text.replace("\r", "")
         text = text.replace("\t", " " * 8)
         text = re.sub("(?i)<style>.*?</style>", "", text)
         text = re.sub(r"\[\[type:[^]]+\]\]", "", text)