Is there a simple way to subset a GRangesList by its seqnames (for example, select only transcripts in chromosome 1)?

I tried this:

gr1 = GRanges(seqnames = "chr2",
               ranges = IRanges(103, 106),
               strand = "+",
               score = 5L, GC = 0.45)

gr2 = GRanges(seqnames = c("chr1", "chr1"),
               ranges = IRanges(c(107, 113), width = 3),
               strand = c("+", "-"),
               score = 3:4, GC = c(0.3, 0.5))

grl = GRangesList(txA = gr1, txB = gr2)

grl_chr1 = grl[seqnames(grl) == "chr1"]

But grl_chr1 is a GRangesList with the same length as grl with its first element as a zero-length GRanges object. Is there a simple way to remove all zero-length elements from a GRangesList so that I can get a new GRangesList with only transcripts from chr1?

> gr1 = GRanges(seqnames = "chr2",
               ranges = IRanges(103, 106),
               strand = "+",
               score = 5L, GC = 0.45)

gr2 = GRanges(seqnames = c("chr1", "chr1"),
               ranges = IRanges(c(107, 113), width = 3),
               strand = c("+", "-"),
               score = 3:4, GC = c(0.3, 0.5))

grl = GRangesList(txA = gr1, txB = gr2)
gr1 = GRanges(seqnames = "chr2",
+                ranges = IRanges(103, 106),
+                strand = "+",
+                score = 5L, GC = 0.45)
> 
> gr2 = GRanges(seqnames = c("chr1", "chr1"),
+                ranges = IRanges(c(107, 113), width = 3),
+                strand = c("+", "-"),
+                score = 3:4, GC = c(0.3, 0.5))
> 
> grl = GRangesList(txA = gr1, txB = gr2)
> subsetByOverlaps(grl, GRanges("chr1:1-1000"))
GRangesList object of length 1:
$txB
GRanges object with 2 ranges and 2 metadata columns:
      seqnames    ranges strand |     score        GC
         <Rle> <IRanges>  <Rle> | <integer> <numeric>
  [1]     chr1   107-109      + |         3       0.3
  [2]     chr1   113-115      - |         4       0.5
  -------
  seqinfo: 2 sequences from an unspecified genome; no seqlengths