iOS, remove linker warnings (version mismatch).

The Qt libraries are compiled as iOS 10.0, we link
as iOS 8.0, this is a problem waiting to happen. First
time we use a Qt function that uses a iOS 10.0 specific
function the app will crash.

Bumping iOS minimum version from 8.0 to 10.0
Removing the 76x icon, which are not valid from 10.0 and forward

Signed-off-by: Jan Iversen <jani@apache.org>

packaging/ios/Subsurface-mobile/Subsurface-mobile.pro

@@ -222,5 +222,5 @@ ios {
 	images.files = ../../../icons/subsurface-mobile-icon.png
 	QMAKE_BUNDLE_DATA += app_launch_images images
 	QMAKE_INFO_PLIST = ../Info.plist
-	QMAKE_IOS_DEPLOYMENT_TARGET = 8.0
+	QMAKE_IOS_DEPLOYMENT_TARGET = 10.0
 }

packaging/ios/storeIcon.xcassets/AppIcon.appiconset/Contents.json

@@ -84,12 +84,6 @@
       "filename" : "AppIcon40x40@2x.png",
       "scale" : "2x"
     },
-    {
-      "size" : "76x76",
-      "idiom" : "ipad",
-      "filename" : "AppIcon-76.png",
-      "scale" : "1x"
-    },
     {
       "size" : "76x76",
       "idiom" : "ipad",
@@ -113,4 +107,4 @@
     "version" : 1,
     "author" : "xcode"
   }
-}
+}