Remove double thus (#6739)

Author: arturcarvalho

R/utilities-help.R

@@ -90,7 +90,7 @@ rd_orientation <- function() {
   c(
     "@section Orientation: ",
     paste(
-      'This geom treats each axis differently and, thus, can thus have two orientations.',
+      'This geom treats each axis differently and, thus, can have two orientations.',
       'Often the orientation is easy to deduce from a combination of the given',
       'mappings and the types of positional scales in use. Thus, ggplot2 will by',
       'default try to guess which orientation the layer should have. Under rare',