Fix wrong bracket in logging statement

The 'sep' argument belongs to the 'paste' function, not to the 'logging'
function. Move the wrongly placed bracket to the right place (also to
prevent a warning being printed).

Signed-off-by: Thomas Bock <bockthom@cs.uni-saarland.de>

util-networks-covariates.R

@@ -1618,7 +1618,7 @@ get.first.activity.data = function(range.data, activity.types = c("commits", "ma
 
     for (missing.key in missing.keys) {
         logging::logwarn(paste("The type", missing.key, "was configured but the RangeData did not contain any",
-                                 "activities of that type"), sep = " ")
+                                 "activities of that type", sep = " "))
         activity.by.type[missing.key] = na.list
     }