Fix grammar problem (#5078)

Fixes #5077

Author: roji

entity-framework/core/miscellaneous/connection-resiliency.md

@@ -49,7 +49,7 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
 
 An execution strategy that automatically retries on failures needs to be able to play back each operation in a retry block that fails. When retries are enabled, each operation you perform via EF Core becomes its own retriable operation. That is, each query and each call to `SaveChangesAsync()` will be retried as a unit if a transient failure occurs.
 
-However, if your code initiates a transaction using `BeginTransactionAsync()` you are defining your own group of operations that need to be treated as a unit, and everything inside the transaction would need to be played back shall a failure occur. You will receive an exception like the following if you attempt to do this when using an execution strategy:
+However, if your code initiates a transaction using `BeginTransactionAsync()` you are defining your own group of operations that need to be treated as a unit, and everything inside the transaction would need to be played back if a failure occurs. You will receive an exception like the following if you attempt to do this when using an execution strategy:
 
 > InvalidOperationException: The configured execution strategy 'SqlServerRetryingExecutionStrategy' does not support user-initiated transactions. Use the execution strategy returned by 'DbContext.Database.CreateExecutionStrategy()' to execute all the operations in the transaction as a retriable unit.