Add real KPM to historical detail table and fix kills per match labels

frontend/historico-partida.html

@@ -138,6 +138,7 @@
                     <option value="deaths">Muertes</option>
                     <option value="teamkills">TK</option>
                     <option value="kd">KD</option>
+                    <option value="kpm">KPM</option>
                     <option value="name">Jugador</option>
                   </select>
                 </label>
@@ -159,6 +160,7 @@
                       <th>Muertes</th>
                       <th>TK</th>
                       <th>KD</th>
+                      <th>KPM</th>
                     </tr>
                   </thead>
                   <tbody id="match-detail-players-body"></tbody>