Fix typo

Author: josephpab

MSAL/src/configuration/MSALLoggerConfig.m

@@ -57,7 +57,7 @@ - (void)setLogCallback:(MSALLogCallback)callback
 #if DEBUG
         @throw [NSException
                 exceptionWithName:NSInternalInconsistencyException
-                reason:@"MSAL logging callback can only be set once per process and should never changed be once set."
+                reason:@"MSAL logging callback can only be set once per process and should never be changed once set."
                 userInfo:nil];
 #endif
         MSID_LOG_WITH_CTX(MSIDLogLevelError, nil, @"MSAL logging callback can only be set once per process and should never be changed once set.");