Allow using icons without custom class

app/views/icons/_nostrich-head.html.erb

@@ -1,4 +1,4 @@
-<svg width="24" height="24" class="icon-nostrich-head <%= custom_class %>" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+<svg width="24" height="24" class="icon-nostrich-head <%= local_assigns[:custom_class] %>" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
   <path d="M3.03377 4.84648C2.38935 5.60878 1.88639 6.49681 1.5799 7.4713C3.32454 7.07836 5.64286 6.98406 6.95527 6.88189C7.36392 5.20013 8.52701 3.91915 10.476 4.0056C11.3169 4.04489 12.0556 4.58714 12.5664 5.42017C12.9436 5.01937 13.4466 4.75218 14.1146 4.65787C14.1617 4.65787 14.2639 4.65001 14.3425 4.65001C12.9593 3.14114 10.9868 2.18237 8.77849 2.18237C8.3777 2.18237 7.98476 2.22167 7.59183 2.28454C7.51324 2.28454 7.41108 2.30026 7.27748 2.33169C7.26962 2.33169 7.2539 2.33169 7.24604 2.33169C7.23818 2.33169 7.23032 2.33169 7.21461 2.33169C5.69001 2.70105 4.54264 2.40242 3.89037 1.51438C3.81964 1.42008 3.54458 1.00357 3.45814 0.272705C2.97876 0.767805 2.66441 1.58511 2.9316 2.45743C3.14379 3.149 3.54458 3.51836 3.97681 3.73054C3.31668 3.76984 2.76657 3.6441 2.21646 3.22759C1.89425 2.98396 1.68992 2.71677 1.352 2.01734C1.03765 2.51244 1.06909 3.06255 1.13195 3.34547C1.21054 3.72268 1.40701 4.14706 1.65849 4.39068C2.04357 4.76789 2.59368 4.85434 3.04162 4.84648H3.03377Z" fill="currentColor"/>
   <path d="M10.4837 11.3458C11.4602 11.3458 12.2519 9.99116 12.2519 8.32016C12.2519 6.64917 11.4602 5.29456 10.4837 5.29456C9.50711 5.29456 8.71545 6.64917 8.71545 8.32016C8.71545 9.99116 9.50711 11.3458 10.4837 11.3458Z" fill="currentColor"/>
   <path d="M14.3737 10.615C15.1376 10.615 15.7569 9.53831 15.7569 8.21019C15.7569 6.88207 15.1376 5.80542 14.3737 5.80542C13.6099 5.80542 12.9906 6.88207 12.9906 8.21019C12.9906 9.53831 13.6099 10.615 14.3737 10.615Z" fill="currentColor"/>