Fix syntax error in Github issue template

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -48,7 +48,7 @@ body:
                   - For which purpose do you use the project ?
                   - With which software/hardware it is integrated ?
                   - Did you use sip.linphone.org or a different SIP service (in this case specify which one and which version) ?
-    placeholder: |
+    value: |
             I use this project in a custom app running on Linux with the sip.linphone.org service for my company. I want to do a simple call between an Android phone and a Linux client. There is an error with a method of this project and I'm sure that I followed the documentation and double checked before posting.
   validations:
     required: true
@@ -65,11 +65,11 @@ body:
                   - OS: [e.g. Android 11]
                   - Version of the App [e.g. 4.3.1]
                   - Version of the SDK [e.g 4.4.16]
-  placeholder: |
-                - Device:
-                - OS:
-                - Version of the App:
-                - Version of the SDK:
+    value: |
+                  - Device:
+                  - OS:
+                  - Version of the App:
+                  - Version of the SDK:
   validations:
     required: true
 
@@ -77,7 +77,7 @@ body:
   attributes:
     label: Expected behaviour
     description: "A clear and concise description of what you expected to happen."
-    placeholder: |
+    value: |
             I wanted to do a simple call with the Linux client calling the Android phone. However, the phone doesn't ring when it is asleep.
   validations:
     required: true
@@ -86,7 +86,7 @@ body:
   attributes:
     label: To Reproduce
     description: "Steps to reproduce the behavior:"
-    placeholder: |
+    value: |
             1. Go to '...'
             2. Click on '....'
             3. Scroll down to '....'
@@ -97,7 +97,7 @@ body:
 - type: textarea
   attributes:
     label: 'Additional context'
-    placeholder: Add any other context about the problem here.
+    value: Add any other context about the problem here.
 
 - type: markdown
   attributes: