Small optimization for QuickLatex: Reducing DB writes

Hi!

I noticed that update_option() is being called on each page load even when no changes are made. To save some database resources, I’ve slightly refactored the code to use a flag ($needs_update).

This way, the DB is only touched if a setting is actually missing or updated. I also cleaned up the repetitive checks with a quick loop.

Here is the suggested change for lines 201-275

// Check if we have options in DB. Write defaults if not.
		$g_options = get_option('quicklatex');

		if ($g_options === false) {
			// Write default options to DB for the first time
			update_option('quicklatex', $def_options);
			$g_options = $def_options;
		} else {
			// This flag tracks if any changes were made during the checks
			$needs_update = false;

			// 1. AMS Packages - Check if preamble needs correction
			if (!isset($g_options['is_preamble_corrected'])) {
				$preamble = trim($g_options['preamble'] ?? '');
				
				if ($preamble == '') {
					// Setup default AMS packages if preamble is empty
					$preamble = "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n";
				} else {
					// Check for individual packages and prepend if missing
					if (strpos($preamble, "amssymb")  === false) $preamble = "\\usepackage{amssymb}\n" . $preamble;
					if (strpos($preamble, "amsfonts") === false) $preamble = "\\usepackage{amsfonts}\n" . $preamble;
					if (strpos($preamble, "amsmath")  === false) $preamble = "\\usepackage{amsmath}\n" . $preamble;
				}

				$g_options['preamble'] = $preamble;
				$g_options['is_preamble_corrected'] = 1;
				$needs_update = true;
			}

			// 2. Default settings for missing fields
			$fields_to_check = [
				'displayed_equations_align' => 0,
				'eqno_align'                => 0,
				'latex_syntax'              => 0,
				'exclude_dollars'           => 0,
			];

			foreach ($fields_to_check as $key => $default_value) {
				if (!isset($g_options[$key])) {
					$g_options[$key] = $default_value;
					$needs_update = true;
				}
			}

			// 3. Image Format Logic
			if (!isset($g_options['image_format'])) {
				$g_options['image_format'] = 1; // Set default to PNG
				$needs_update = true;
			} elseif ($g_options['image_format'] == 0) {
				// Migration: Switch from GIF (0) to PNG (1)
				$g_options['image_format'] = 1;
				$needs_update = true;
			}

			// Final Step: Only update the database if a change was actually made
			if ($needs_update) {
				update_option('quicklatex', $g_options);
			}
		}

Bests,
Lena