refactor(http_exporter): add empty space in logs

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/_log_exporter/__init__.py

@@ -215,7 +215,7 @@ def export(
                 or self._shutdown
             ):
                 _logger.error(
-                    "Failed to export logs batch due to timeout,"
+                    "Failed to export logs batch due to timeout, "
                     "max retries or shutdown."
                 )
                 return LogRecordExportResult.FAILURE

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/metric_exporter/__init__.py

@@ -259,7 +259,7 @@ def export(
                 or self._shutdown
             ):
                 _logger.error(
-                    "Failed to export metrics batch due to timeout,"
+                    "Failed to export metrics batch due to timeout, "
                     "max retries or shutdown."
                 )
                 return MetricExportResult.FAILURE

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/trace_exporter/__init__.py

@@ -208,7 +208,7 @@ def export(self, spans: Sequence[ReadableSpan]) -> SpanExportResult:
                 or self._shutdown
             ):
                 _logger.error(
-                    "Failed to export span batch due to timeout,"
+                    "Failed to export span batch due to timeout, "
                     "max retries or shutdown."
                 )
                 return SpanExportResult.FAILURE