[libcalamares] Handle multiple invalid URLs at once

- expand tests with example where more than one URL is invalid
- fix the call to the wrong overload of QVector::erase()

src/libcalamares/network/Manager.cpp

@@ -222,7 +222,7 @@ Manager::setCheckHasInternetUrl( const QVector< QUrl >& urls )
         d->m_hasInternetUrls.begin(), d->m_hasInternetUrls.end(), []( const QUrl& u ) { return !u.isValid(); } );
     if ( it != d->m_hasInternetUrls.end() )
     {
-        d->m_hasInternetUrls.erase( it );
+        d->m_hasInternetUrls.erase( it, d->m_hasInternetUrls.end() );
     }
 }
 

src/libcalamares/network/Tests.cpp

@@ -134,4 +134,14 @@ NetworkTests::testCheckMultiUrl()
         QVERIFY( nam.checkHasInternet() );
         QCOMPARE( nam.getCheckInternetUrls().count(), 2 );
     }
+    {
+        QUrl u0( "http://nonexistent.example.com" );
+        QUrl u1;
+        QVERIFY( u0.isValid() );
+        QVERIFY( !u1.isValid() );
+        nam.setCheckHasInternetUrl( { u1, u1, u1, u1 } );
+        QCOMPARE( nam.getCheckInternetUrls().count(), 0 );
+        nam.setCheckHasInternetUrl( { u1, u1, u0, u1 } );
+        QCOMPARE( nam.getCheckInternetUrls().count(), 1 );
+    }
 }