add type check before applying 'browser' option (fixes #1358)

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Changelog
 
+## Unreleased
+
 ## 1.17.0 - 2021-03-05
 ### Additions
 - [cyberdrop] add support for `https://cyberdrop.me/` ([#1328](https://github.com/mikf/gallery-dl/issues/1328))

gallery_dl/extractor/common.py

@@ -216,7 +216,7 @@ class Extractor():
         headers.clear()
 
         browser = self.config("browser") or self.browser
-        if browser:
+        if browser and isinstance(browser, str):
             browser, _, platform = browser.lower().partition(":")
 
             if not platform or platform == "auto":

gallery_dl/version.py

@@ -6,4 +6,4 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.17.0"
+__version__ = "1.17.1-dev"