remove broken link to model

doc/models_library/output.html

@@ -424,10 +424,4 @@ <h3 id="stdp_triplet_synapse-stdp_triplet_synapse"><code
 <p>Synapse type with triplet spike-timing dependent plasticity</p>
 <p>Source file: <a
 href="https://www.github.com/nest/nestml/blob/master/models/synapses/stdp_triplet_synapse.nestml">stdp_triplet_synapse.nestml</a></p>
-<h3 id="third_factor_stdp_synapse-third_factor_stdp_synapse"><code
-class="interpreted-text"
-role="doc">third_factor_stdp_synapse &lt;third_factor_stdp_synapse&gt;</code></h3>
-<p>Synapse model for spike-timing dependent plasticity with postsynaptic
-third-factor modulation</p>
-<p>Source file: <a
-href="https://www.github.com/nest/nestml/blob/master/models/synapses/third_factor_stdp_synapse.nestml">third_factor_stdp_synapse.nestml</a></p>
+