OLMKit: Fixed type of messageIndex argument in exportSessionAtMessageIndex

Signed-off-by: Greg Hughes <greg@ghughes.com>

xcode/OLMKit/OLMInboundGroupSession.h

@@ -33,6 +33,6 @@
 
 - (BOOL)isVerified;
 
-- (NSString*)exportSessionAtMessageIndex:(NSUInteger*)messageIndex error:(NSError**)error;
+- (NSString*)exportSessionAtMessageIndex:(NSUInteger)messageIndex error:(NSError**)error;
 
 @end

xcode/OLMKit/OLMInboundGroupSession.m

@@ -190,7 +190,7 @@
     return (0 != olm_inbound_group_session_is_verified(session));
 }
 
-- (NSString*)exportSessionAtMessageIndex:(NSUInteger*)messageIndex error:(NSError**)error;
+- (NSString*)exportSessionAtMessageIndex:(NSUInteger)messageIndex error:(NSError**)error;
 {
     size_t length = olm_export_inbound_group_session_length(session);
     NSMutableData *key = [NSMutableData dataWithLength:length];