fix simple test input

Signed-off-by: Santiago Figueroa Manrique <figueroa1395@gmail.com>

Author: figueroa1395

tests/data/state_estimation/basic-current-sensor/input.json

@@ -18,7 +18,7 @@
       {"id": 5, "node": 2, "status": 1, "type": 0}
     ],
     "sym_voltage_sensor": [
-      {"id": 6, "measured_object": 1, "u_sigma": 200, "u_measured": 10000}
+      {"id": 6, "measured_object": 1, "u_sigma": 200, "u_measured": 10000, "u_angle_measured": 0.0}
     ],
     "sym_current_sensor": [
       {"id": 7, "measured_object": 3, "measured_terminal_type": 0, "angle_measurement_type": 1, "i_sigma": 1, "i_angle_sigma": 0.05, "i_measured": 10, "i_angle_measured": 0.3}