LedgerAlign: Better detect decimal point

This commit detect the location of the decimal point consistently in the
following circumstances (given g:ledger_decimal_sep='.'):

    -30 = 0
    456.78

It uses the decimal point location if it can be found, and if it cannot,
it uses the first character after the first group of digits.

Author: Mildred Ki'Lya

autoload/ledger.vim

@@ -373,12 +373,15 @@ function! ledger#align_commodity()
   if rhs != ''
     " Remove everything after the account name (including spaces):
     .s/\m^\s\+[^[:space:]].\{-}\zs\(\t\|  \).*$//
-    if g:ledger_decimal_sep == ''
-      let pos = matchend(rhs, '\m\d[^[:space:]]*')
-    else
+    let pos = -1
+    if g:ledger_decimal_sep != ''
       " Find the position of the first decimal separator:
       let pos = s:strpos(rhs, '\V' . g:ledger_decimal_sep)
     endif
+    if pos < 0
+      " Find the position after the first digits
+      let pos = matchend(rhs, '\m\d[^[:space:]]*')
+    endif
     " Go to the column that allows us to align the decimal separator at g:ledger_align_at:
     if pos > 0
       call s:goto_col(g:ledger_align_at - pos - 1)