fix ios12

Signed-off-by: marinofaggiana <ios@nextcloud.com>

iOSClient/Main/Section Header Footer/NCSectionFooter.xib

@@ -29,7 +29,7 @@
                         <action selector="touchUpInsideButton:" destination="Vin-9E-7nW" eventType="touchUpInside" id="XSh-0v-WHJ"/>
                     </connections>
                 </button>
-                <activityIndicatorView opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" style="medium" translatesAutoresizingMaskIntoConstraints="NO" id="qWG-SR-Qly">
+                <activityIndicatorView opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" style="gray" translatesAutoresizingMaskIntoConstraints="NO" id="qWG-SR-Qly">
                     <rect key="frame" x="177.5" y="5" width="20" height="20"/>
                 </activityIndicatorView>
                 <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="s2m-yO-4x0" userLabel="separator">