Update start_aws.md (fastai#428)

changed conda install -c pytorch -c fastai fastai pytorch torchvision cuda92
to conda install -c pytorch -c fastai fastai as the previous one  will break the environment 
Deep Learning AMI (Ubuntu) Version 16.0 is no longer recommend by AWS, so the doc should be updated to Version 24.1

docs/start_aws.md

@@ -87,7 +87,7 @@ Log in to the AWS console then search for EC2 in the query bar or click 'EC2' in
 
 <img alt="launch instance" src="/images/aws/launch_instance.png" class="screenshot">
 
-Search for 'deep learning' and select the first option: Deep Learning AMI (Ubuntu) Version 16.0
+Search for 'deep learning' and select the first option: Deep Learning AMI (Ubuntu) Version 24.1
 
 <img alt="amiubuntu" src="/images/aws/amiubuntu.png" class="screenshot">
 
@@ -136,7 +136,7 @@ Then run these commands to install the necessary packages for experimenting with
 
 ``` bash
 conda update conda
-conda install -c pytorch -c fastai fastai pytorch torchvision cuda92
+conda install -c pytorch -c fastai fastai pytorch 
 ```
 
 Next move into the directory where you will find the materials for the course by running: