Fix whitespace in APIv3 Blueprint

Signed-off-by: Alex Coles <alex@alexbcoles.com>

doc/apiv3-documentation.apib

@@ -1154,7 +1154,7 @@ A user must have the permission to **edit journals** to update an activity. A
 
 + Parameters
     + id (required, integer, `1`) ... Work package id
-    
+
 + Request (application/json)
 
         {
@@ -1669,7 +1669,7 @@ A user must have the permission to **create journals** to update an activity. A
 
 + Model
     + Body
-    
+
             {
                 "_total": 1674,
                 "_embedded": {
@@ -1746,7 +1746,7 @@ Gets a list of users that can be assigned to the work package.
 
 + Model
     + Body
-    
+
             {
                 "_total": 1674,
                 "_embedded": {
@@ -1823,7 +1823,7 @@ Gets a list of users that can be assigned to the work package as responsible.
 
 + Model
     + Body
-    
+
             {
                 "_total": 1674,
                 "_count": 1,
@@ -1865,4 +1865,3 @@ Gets a list of users that can watch the work package.
 + Response 200 (application/hal+json)
 
     [AvailableWatchers][]
-