Don't modify Collection while iterating over it

Removing list element using Collection.remove() invalidates Iterator
and results in incorrect behaviour.

Author: mizdebsk

xmvn-api/src/main/java/org/fedoraproject/xmvn/deployer/DeploymentRequest.java

@@ -77,10 +77,9 @@ public void removeDependency( Artifact dependencyArtifact )
         Iterator<DependencyDescriptor> ddl = dependencies.iterator();
         while ( ddl.hasNext() )
         {
-            DependencyDescriptor dd = ddl.next();
-            if ( dd.getDependencyArtifact().equals( dependencyArtifact ) )
+            if ( ddl.next().getDependencyArtifact().equals( dependencyArtifact ) )
             {
-                dependencies.remove( dd );
+                ddl.remove();
             }
         }
     }

xmvn-api/src/test/java/org/fedoraproject/xmvn/deployer/DeploymentRequestTest.java

@@ -138,13 +138,13 @@ public void addAndGetDependenciesTest()
 
         deployRq.addDependency( dependencyB, dependencyC, dependencyD );
         listedDependencies = deployRq.getDependencies();
-        Assert.assertTrue( listedDependencies.get( 1 ).getExclusions().equals( depExcl ) );
+        Assert.assertTrue( listedDependencies.get( 0 ).getExclusions().equals( depExcl ) );
         deployRq.removeDependency( dependencyB );
 
         // tests adding optional dependency without exclusions
         deployRq.addDependency( dependencyB, true, new ArrayList<>() );
         listedDependencies = deployRq.getDependencies();
-        dsc = listedDependencies.get( 1 );
+        dsc = listedDependencies.get( 0 );
         Assert.assertTrue( dsc.isOptional() );
         Assert.assertTrue( dsc.getExclusions().isEmpty() );