Update Exercise_04_2_solution.ipynb

add missing comma

Author: jglombitza

Exercise_04_2_solution.ipynb

@@ -88,7 +88,7 @@
     "    def __init__(self, units=1, input_dim=1):  # when intializing the layer the weights have to be initialized\n",
     "        super(LinearLayer, self).__init__()\n",
     "        w_init = tf.random_normal_initializer()\n",
-    "        self.w = self.add_weight(shape=(input_dim, units), initializer=w_init\n",
+    "        self.w = self.add_weight(shape=(input_dim, units), initializer=w_init,\n",
     "                                 trainable=True)\n",
     "\n",
     "    def call(self, inputs):  # when calling the layer the linear transformation has to be performed\n",