Update .env.example

services/engine/.env.example

@@ -8,7 +8,7 @@ AGENT_MAX_ITERATIONS = 15
 #timeout in seconds for the engine to return a response. Defaults to 150 seconds
 DH_ENGINE_TIMEOUT = 150
 #tmeout for SQL execution, our agents exceute the SQL query to recover from errors, this is the timeout for that execution. Defaults to 30 seconds
-SQL_EXECUTION_TIMEOUT =
+SQL_EXECUTION_TIMEOUT = 30
 #The upper limit on number of rows returned from the query engine (equivalent to using LIMIT N in PostgreSQL/MySQL/SQlite). Defauls to 50
 UPPER_LIMIT_QUERY_RETURN_ROWS = 50
 #Encryption key for storing DB connection data in Mongo