fix easy typo

src/or/or.h

@@ -4015,7 +4015,7 @@ typedef struct {
   char *ConsensusParams;
 
   /** Authority only: minimum number of measured bandwidths we must see
-   * before we only beliee measured bandwidths to assign flags. */
+   * before we only believe measured bandwidths to assign flags. */
   int MinMeasuredBWsForAuthToIgnoreAdvertised;
 
   /** The length of time that we think an initial consensus should be fresh.