1) Fix network disconnect issue while establishing the connection via SSH Tunnel and it impossible to expand the Servers node. Fixes #4724.

2) Fix server connection drops out issue in query tool. Fixes #4818
3) Fix VPN network disconnect issue where pgAdmin4 hangs on expanding the Servers node. Fixes #4926.
4) Ensure that the Servers collection node should expand independently of server connections. Fixes #4933.

Set the default connection timeout to 10 seconds instead of 0.

web/migrations/versions/aff1436e3c8c_.py

@@ -0,0 +1,27 @@
+
+""" Update the default timeout to 10 seconds instead on 0.
+0 indicates wait indefinitely which causes trouble when network connection
+to server is lost.
+
+Revision ID: aff1436e3c8c
+Revises: a77a0932a568
+Create Date: 2019-10-28 12:47:36.828709
+
+"""
+from pgadmin.model import db
+
+# revision identifiers, used by Alembic.
+revision = 'aff1436e3c8c'
+down_revision = 'a77a0932a568'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    db.engine.execute(
+        'UPDATE server SET connect_timeout=10 WHERE connect_timeout=0 OR connect_timeout IS NULL'
+    )
+
+
+def downgrade():
+    pass