Fixes a bug where the number of executors always revers to the default for that
type of AMI, and ignores what the user has set.

Index: src/main/java/hudson/plugins/ec2/EC2Slave.java
===================================================================
— src/main/java/hudson/plugins/ec2/EC2Slave.java (revision 23764)
+++ src/main/java/hudson/plugins/ec2/EC2Slave.java (working copy)
@@ -30,8 +30,8 @@
*/
public final String initScript;

• public EC2Slave(String instanceId, String description, String remoteFS,
  InstanceType type, String label, String initScript) throws FormException,
  IOException {
• this(instanceId, description, remoteFS, toNumExecutors(type),
  Mode.NORMAL, label, initScript, Collections.<NodeProperty<?>>emptyList());
  + public EC2Slave(String instanceId, String description, String remoteFS,
  InstanceType type, int numExecutors, String label, String initScript) throws
  FormException, IOException { + this(instanceId, description, remoteFS, numExecutors, Mode.NORMAL, label, initScript, Collections.<NodeProperty<?>>emptyList()); }

@DataBoundConstructor
Index: src/main/java/hudson/plugins/ec2/SlaveTemplate.java
===================================================================
— src/main/java/hudson/plugins/ec2/SlaveTemplate.java (revision 23764)
+++ src/main/java/hudson/plugins/ec2/SlaveTemplate.java (working copy)
@@ -98,7 +98,7 @@
throw new EC2Exception("No matching keypair found on EC2. Is
the EC2 private key a valid one?");
Instance inst = ec2.runInstances(ami, 1, 1,
Collections.<String>emptyList(), userData, keyPair.getKeyName(),
type).getInstances().get(0);

• return new EC2Slave(inst.getInstanceId(),description,remoteFS,type,
  labels,initScript);
  + return new EC2Slave(inst.getInstanceId(),description,remoteFS,type,
  getNumExecutors(),labels,initScript);
  } catch (FormException e) { throw new AssertionError(); // we should have discovered all configuration issues upfront }
  @@ -116,7 +116,7 @@
  logger.println("Attaching to "+instanceId);
  Instance inst =
  ec2.describeInstances(Collections.singletonList(instanceId)).get(0).getInstances().get(0);
  
  - return new EC2Slave(inst.getInstanceId(),description,remoteFS,type,
  labels,initScript);
  + return new EC2Slave(inst.getInstanceId(),description,remoteFS,type,
  getNumExecutors(),labels,initScript);
  } catch (FormException e) { throw new AssertionError(); // we should have discovered allconfiguration issues upfront }