[3.6] Fix error message in sqlite connection thread check. (GH-6028). (GH-6324)

(cherry picked from commit 030345c0)
Co-authored-by: Takuya Akiba <469803+iwiwi@users.noreply.github.com>

Modules/_sqlite/connection.c

@@ -1125,8 +1125,8 @@ int pysqlite_check_thread(pysqlite_Connection* self)
     if (self->check_same_thread) {
         if (PyThread_get_thread_ident() != self->thread_ident) {
             PyErr_Format(pysqlite_ProgrammingError,
-                        "SQLite objects created in a thread can only be used in that same thread."
-                        "The object was created in thread id %ld and this is thread id %ld",
+                        "SQLite objects created in a thread can only be used in that same thread. "
+                        "The object was created in thread id %ld and this is thread id %ld.",
                         self->thread_ident, PyThread_get_thread_ident());
             return 0;
         }