mark smtp fields as not required

.env.example

@@ -31,12 +31,12 @@ MONGO_PASSWORD=example
 SITE_URL=http://localhost:8080
 
 # Mail/SMTP
-SMTP_HOST= # required
-SMTP_USERNAME= # required
-SMTP_PASSWORD= # required
+SMTP_HOST= 
+SMTP_USERNAME= 
+SMTP_PASSWORD= 
 SMTP_PORT=587
 SMTP_SECURE=false
-SMTP_FROM_ADDRESS= # required
+SMTP_FROM_ADDRESS= 
 SMTP_FROM_NAME=Infisical
 
 # Integration
@@ -66,4 +66,4 @@ STRIPE_WEBHOOK_SECRET=
 STRIPE_PRODUCT_STARTER=
 STRIPE_PRODUCT_TEAM=
 STRIPE_PRODUCT_PRO=
-NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=
+NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=