Minor fixes in three error messages

* Fix "can not" -> "cannot" in two messages
* Re-word "Cannot mkdir" to "Cannot create directory"

Change-Id: Ide0cec55eeeebd23bccc136257c80f47638ba858
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -62,7 +62,7 @@ cannotCreateDirectory=Cannot create directory {0}
 cannotCreateHEAD=cannot create HEAD
 cannotCreateIndexfile=Cannot create an index file with name {0}
 cannotCreateTempDir=Cannot create a temp dir
-cannotDeleteCheckedOutBranch=Branch {0} is checked out and can not be deleted
+cannotDeleteCheckedOutBranch=Branch {0} is checked out and cannot be deleted
 cannotDeleteFile=Cannot delete file: {0}
 cannotDeleteObjectsPath=Cannot delete {0}/{1}: {2}
 cannotDeleteStaleTrackingRef=Cannot delete stale tracking ref {0}
@@ -80,7 +80,7 @@ cannotListRefs=cannot list refs
 cannotLock=Cannot lock {0}. Ensure that no other process has an open file handle on the lock file {0}.lock, then you may delete the lock file and retry.
 cannotLockPackIn=Cannot lock pack in {0}
 cannotMatchOnEmptyString=Cannot match on empty string.
-cannotMkdirObjectPath=Cannot mkdir {0}/{1}: {2}
+cannotMkdirObjectPath=Cannot create directory {0}/{1}: {2}
 cannotMoveIndexTo=Cannot move index to {0}
 cannotMovePackTo=Cannot move pack to {0}
 cannotOpenService=cannot open {0}
@@ -547,7 +547,7 @@ redirectsOff=Cannot redirect because http.followRedirects is false (HTTP status
 refAlreadyExists=already exists
 refAlreadyExists1=Ref {0} already exists
 reflogEntryNotFound=Entry {0} not found  in reflog for ''{1}''
-refNotResolved=Ref {0} can not be resolved
+refNotResolved=Ref {0} cannot be resolved
 refUpdateReturnCodeWas=RefUpdate return code was: {0}
 remoteConfigHasNoURIAssociated=Remote config "{0}" has no URIs associated
 remoteDoesNotHaveSpec=Remote does not have {0} available for fetch.