Prevent failed to create new store connection exception

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -70,6 +70,8 @@ public class MessageHelper {
         props.put("mail.imaps.timeout", "20000");
         props.put("mail.imaps.writetimeout", "20000"); // one thread overhead
 
+        props.put("mail.imaps.connectionpooltimeout", Integer.toString(3 * 60 * 1000)); // default: 45 sec
+
         // https://javaee.github.io/javamail/docs/api/com/sun/mail/smtp/package-summary.html#properties
         props.put("mail.smtps.ssl.checkserveridentity", "true");
         props.put("mail.smtps.ssl.trust", "*");

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -469,6 +469,7 @@ public class ServiceSynchronize extends LifecycleService {
                     db.folder().setFolderState(folder.id, null);
                 db.account().setAccountState(account.id, "connecting");
                 istore.connect(account.host, account.port, account.user, account.password);
+                boolean hasIdle = istore.hasCapability("IDLE");
 
                 backoff = CONNECT_BACKOFF_START;
                 db.account().setAccountState(account.id, "connected");
@@ -627,7 +628,7 @@ public class ServiceSynchronize extends LifecycleService {
                     noops.add(noop);
 
                     // Receive folder events
-                    if (istore.hasCapability("IDLE")) {
+                    if (hasIdle) {
                         Thread idle = new Thread(new Runnable() {
                             @Override
                             public void run() {