check_sqlite_table: also check if entires in table

code that uses this funciton assume the table is present and sometimes
also that there are entries in the table (table is not empty). To ensure
this does not crash in instances where the table is present but is
empty, also check that the table is not empty.

massdash/util.py

@@ -235,7 +235,10 @@ def check_sqlite_table(con, table):
     result = con.execute('SELECT count(name) FROM sqlite_master WHERE type="table" AND name=?', (table,))
 
     if result.fetchone()[0] == 1:
-        table_present = True
+        # ensure the table is not empty
+        result = con.execute(f"SELECT COUNT(*) FROM {table}")
+        if result.fetchone()[0] > 0:
+            table_present = True
 
     return table_present