Increase retries for gcc sources download

This in order to try to reduce likelihood of getting
```
Failed to open TCP connection to ftp.gnu.org:443 (Network is unreachable - connect(2) for "ftp.gnu.org" port 443)
```

Signed-off-by: Luca Carrogu <[email protected]>

Author: lukeseawalker

cookbooks/aws-parallelcluster-install/recipes/arm_pl.rb

@@ -65,8 +65,8 @@
 remote_file gcc_tarball do
   source node['cluster']['armpl']['gcc']['url']
   mode '0644'
-  retries 3
-  retry_delay 5
+  retries 5
+  retry_delay 10
   not_if { ::File.exist?(gcc_tarball) }
 end