refactor: re-order PRAGMA statements (XRPLF#5140)

The page_size will soon be made configurable with XRPLF#5135, making this
re-ordering necessary.

When opening SQLite connection, there are specific pragmas set with
commonPragmas.

In particular, PRAGMA journal_mode creates journal file and locks the
page_size; as of this commit, this sets the page size to the default
value of 4096. Coincidentally, the hardcoded page_size was also 4096, so
no issue was noticed.

src/xrpld/core/DatabaseCon.h

@@ -206,6 +206,12 @@ class DatabaseCon
     {
         open(*session_, "sqlite", pPath.string());
 
+        for (auto const& p : pragma)
+        {
+            soci::statement st = session_->prepare << p;
+            st.execute(true);
+        }
+
         if (commonPragma)
         {
             for (auto const& p : *commonPragma)
@@ -214,11 +220,7 @@ class DatabaseCon
                 st.execute(true);
             }
         }
-        for (auto const& p : pragma)
-        {
-            soci::statement st = session_->prepare << p;
-            st.execute(true);
-        }
+
         for (auto const& sql : initSQL)
         {
             soci::statement st = session_->prepare << sql;