core (memory/sql_mapping): remove autoincrement:

SQLite specific behaviour with autoincrement (https://sqlite.org/autoinc.html) is actually
already handled by SQLAlchemy, and unsetting autoincrement cause troubles when storing new
objects.

sat/memory/sqla_mapping.py

@@ -151,9 +151,6 @@ class Profile(Base):
         Integer,
         primary_key=True,
         nullable=True,
-        # settings autoincrement would have negative performance impact
-        # cf. https://sqlite.org/autoinc.html
-        autoincrement=False
     )
     name = Column(Text, unique=True)
 
@@ -316,8 +313,6 @@ class Message(Base):
     id = Column(
         Integer,
         primary_key=True,
-        # cf. note for Profile.id
-        autoincrement=False
     )
     history_uid = Column(ForeignKey("history.uid", ondelete="CASCADE"))
     message = Column(Text)
@@ -339,8 +334,6 @@ class Subject(Base):
     id = Column(
         Integer,
         primary_key=True,
-        # cf. note for Profile.id
-        autoincrement=False,
     )
     history_uid = Column(ForeignKey("history.uid", ondelete="CASCADE"))
     subject = Column(Text)
@@ -362,8 +355,6 @@ class Thread(Base):
     id = Column(
         Integer,
         primary_key=True,
-        # cf. note for Profile.id
-        autoincrement=False,
     )
     history_uid = Column(ForeignKey("history.uid", ondelete="CASCADE"))
     thread_id = Column(Text)