Use PyMySQL rather than MySQL Connector

scripts/check_dependencies.py

@@ -97,7 +97,7 @@ MODULES = [
 
 OPTIONAL_MODULES = [
     ('qdarkstyle', '(dark style support)'),
-    ('mysql.connector', '(MySQL support)'),
+    ('pymysql', '(MySQL support)'),
     ('pyodbc', '(ODBC support)'),
     ('psycopg2', '(PostgreSQL support)'),
     ('enchant', '(spell checker)'),

setup.py

@@ -191,7 +191,7 @@ using a computer and a data projector.""",
     extras_require={
         'agpl-pdf': ['PyMuPDF'],
         'darkstyle': ['QDarkStyle'],
-        'mysql': ['mysql-connector-python'],
+        'mysql': ['pymysql'],
         'odbc': ['pyodbc'],
         'postgresql': ['psycopg2'],
         'spellcheck': ['pyenchant >= 1.6'],