paste: Make is_url an optional parameter in JSON body

Signed-off-by: ATechnoHazard <amolele@gmail.com>

src/core/paste/entity.rs

@@ -5,6 +5,6 @@ use crate::schema::pastes;
 pub struct Paste {
     pub id: Option<String>,
     pub belongs_to: Option<String>,
-    pub is_url: bool,
+    pub is_url: Option<bool>,
     pub content: String,
 }

src/core/paste/service.rs

@@ -5,7 +5,7 @@ use super::entity::Paste;
 use super::postgres;
 
 pub fn create_paste(paste: &mut Paste, conn: &PgConnection) -> Result<usize> {
-    paste.is_url = validator::validate_url(paste.content.clone());
+    paste.is_url = Some(validator::validate_url(paste.content.clone()));
     postgres::create_paste(paste, conn)
 }